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<h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Dreisatz</span></h1>
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<p>Der <b>Dreisatz</b> (in <a href="%C3%96sterreich" title="Österreich">Österreich</a> stattdessen: <i>Schlussrechnung</i>; früher auch: <i>Regeldetri</i>, <i>Regel Detri</i>, <i>Regel de Tri</i> oder <i>Regula de Tri</i> von <span style="font-style:normal;font-weight:normal"><a href="Latein" title="Latein">lateinisch</a></span> <span lang="la-Latn" style="font-style:italic">regula de tribus [terminis]</span> <span lang="de" style="font-style:normal;font-weight:normal">‚Regel von drei [Gliedern]‘</span> bzw. <span style="font-style:normal;font-weight:normal"><a href="Franz%C3%B6sische_Sprache" title="Französische Sprache">französisch</a></span> <span lang="fr-Latn" style="font-style:italic">Règle de trois</span>; auch <i>Goldene Regel</i>, <b>Verhältnisgleichung</b>, <i>Proportionalität</i>, <i>Schlussrechnung</i> oder kurz <i>Schlüsse</i> genannt)<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> ist ein mathematisches Verfahren, um aus drei gegebenen Werten eines <a href="Quotient#Proportionen" title="Quotient">Verhältnisses</a> den unbekannten vierten Wert zu berechnen. Eine (einfachere) Variante ist der <a href="Zweisatz" title="Zweisatz">Zweisatz</a>. Der Dreisatz ist kein <a href="Satz_(Mathematik)" title="Satz (Mathematik)">mathematischer Satz</a>, sondern ein Lösungsverfahren für Proportionalaufgaben. Er wird insbesondere in der Schulmathematik gelehrt. Man kann mit dem Dreisatz Probleme aufgrund einfacher Einsichten oder auch ganz schematisch lösen, ohne die zugrunde liegenden mathematischen Gesetzmäßigkeiten vollständig zu durchschauen. Wer mit <a href="Proportionalit%C3%A4t" title="Proportionalität">Proportionalitäten</a> vertraut ist, benötigt den Dreisatz nicht mehr, weil er dann die Ergebnisse durch einfache mathematische Operationen erhalten kann.
</p>
<div class="mw-heading mw-heading2"><h2 id="Einfacher_Dreisatz">Einfacher Dreisatz</h2></div>
<ul><li>Es liegt eine Gesetzmäßigkeit der Art „Je mehr A, desto mehr B.“ vor (direkte <a href="Proportionalit%C3%A4t" title="Proportionalität">Proportionalität</a>): Beim Verdoppeln (Verdreifachen, …) von A wird auch B verdoppelt (verdreifacht, …).</li>
<li>Gegeben ist ein Verhältnis von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ffd2487510aa438433a2579450ab2b3d557e5edc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.23ex; height:1.676ex;" alt="{\displaystyle a}" loading="lazy"></span> Einheiten einer Größe A zu <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle b}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>b</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle b}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f11423fbb2e967f986e36804a8ae4271734917c3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:0.998ex; height:2.176ex;" alt="{\displaystyle b}" loading="lazy"></span> Einheiten einer Größe B.</li>
<li>Gefragt wird nach der Anzahl <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/87f9e315fd7e2ba406057a97300593c4802b53e4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle x}" loading="lazy"></span> Einheiten der Größe B, die in demselben Verhältnis zu <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>c</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/86a67b81c2de995bd608d5b2df50cd8cd7d92455.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.007ex; height:1.676ex;" alt="{\displaystyle c}" loading="lazy"></span> Einheiten von A stehen.</li></ul>
<p>In einer Tabelle sind die „gleichartigen“ Werte untereinander zu schreiben:
</p>
<table class="wikitable" style="text-align:center;">
<tbody><tr>
<td>Größe A</td>
<td>Größe B
</td></tr>
<tr>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ffd2487510aa438433a2579450ab2b3d557e5edc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.23ex; height:1.676ex;" alt="{\displaystyle a}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle b}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>b</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle b}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f11423fbb2e967f986e36804a8ae4271734917c3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:0.998ex; height:2.176ex;" alt="{\displaystyle b}" loading="lazy"></span>
</td></tr>
<tr>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>c</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/86a67b81c2de995bd608d5b2df50cd8cd7d92455.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.007ex; height:1.676ex;" alt="{\displaystyle c}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/87f9e315fd7e2ba406057a97300593c4802b53e4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle x}" loading="lazy"></span>
</td></tr></tbody></table>
<div class="mw-heading mw-heading3"><h3 id="Inhaltliches_Lösen"><span id="Inhaltliches_L.C3.B6sen"></span>Inhaltliches Lösen</h3></div>
<p>Die Dreisatzaufgabe lässt sich in drei Denkschritten lösen:
</p>
<ol><li><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ffd2487510aa438433a2579450ab2b3d557e5edc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.23ex; height:1.676ex;" alt="{\displaystyle a}" loading="lazy"></span> Einheiten von A entsprechen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle b}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>b</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle b}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f11423fbb2e967f986e36804a8ae4271734917c3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:0.998ex; height:2.176ex;" alt="{\displaystyle b}" loading="lazy"></span> Einheiten von B.</li>
<li>Einer Einheit von A entsprechen <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle b:a}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>b</mi>
<mo>:</mo>
<mi>a</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle b:a}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/0c8399979c8ea2c0a90c7e4b29819cfedb696c4f.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:4.165ex; height:2.176ex;" alt="{\displaystyle b:a}" loading="lazy"></span> Einheiten von B.</li>
<li><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>c</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/86a67b81c2de995bd608d5b2df50cd8cd7d92455.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.007ex; height:1.676ex;" alt="{\displaystyle c}" loading="lazy"></span> Einheiten von A entsprechen also <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x=c\cdot (b:a)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>=</mo>
<mi>c</mi>
<mo>⋅<!-- ⋅ --></mo>
<mo stretchy="false">(</mo>
<mi>b</mi>
<mo>:</mo>
<mi>a</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x=c\cdot (b:a)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/4a9629bc53801ae366a1508767ff8a4f787f0df3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:13.088ex; height:2.843ex;" alt="{\displaystyle x=c\cdot (b:a)}" loading="lazy"></span> Einheiten von B.</li></ol>
<p>In der Tabelle wird eine zusätzliche Zeile eingefügt. In beiden Tabellenspalten wird mit demselben Wert dividiert bzw. multipliziert.
</p>
<table class="wikitable" style="text-align:center;">
<tbody><tr>
<td>Größe A</td>
<td>Größe B</td>
<td>Rechenschritt
</td></tr>
<tr>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ffd2487510aa438433a2579450ab2b3d557e5edc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.23ex; height:1.676ex;" alt="{\displaystyle a}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle b}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>b</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle b}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f11423fbb2e967f986e36804a8ae4271734917c3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:0.998ex; height:2.176ex;" alt="{\displaystyle b}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle :a}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo>:</mo>
<mi>a</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle :a}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f28a12f9884ec490e579882b25642689b529d060.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:2.522ex; height:1.676ex;" alt="{\displaystyle :a}" loading="lazy"></span>
</td></tr>
<tr>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle 1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle 1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/92d98b82a3778f043108d4e20960a9193df57cbf.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.162ex; height:2.176ex;" alt="{\displaystyle 1}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle b:a}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>b</mi>
<mo>:</mo>
<mi>a</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle b:a}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/0c8399979c8ea2c0a90c7e4b29819cfedb696c4f.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:4.165ex; height:2.176ex;" alt="{\displaystyle b:a}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \cdot c}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mo>⋅<!-- ⋅ --></mo>
<mi>c</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle \cdot c}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ed4e74aa106d29427d01ffa4a4fc28ffc942b5fa.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.654ex; height:1.676ex;" alt="{\displaystyle \cdot c}" loading="lazy"></span>
</td></tr>
<tr>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>c</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/86a67b81c2de995bd608d5b2df50cd8cd7d92455.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.007ex; height:1.676ex;" alt="{\displaystyle c}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c\cdot (b:a)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>c</mi>
<mo>⋅<!-- ⋅ --></mo>
<mo stretchy="false">(</mo>
<mi>b</mi>
<mo>:</mo>
<mi>a</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c\cdot (b:a)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/949e0e51c9d7bef062b0f98ee16cfb13f24231ef.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:8.66ex; height:2.843ex;" alt="{\displaystyle c\cdot (b:a)}" loading="lazy"></span></td>
<td>
</td></tr></tbody></table>
<p>Beim Rechnen entstehende <a href="Bruchrechnung" title="Bruchrechnung">Brüche</a> werden in jedem Schritt <a href="K%C3%BCrzen" title="Kürzen">gekürzt</a> (siehe <a href="#Beispiel_1">Beispiel 1</a>).
</p>
<div class="mw-heading mw-heading3"><h3 id="Hintergrund">Hintergrund</h3></div>
<p><a href="Quotient#Proportionen" title="Quotient">Verhältnisse</a> gehören zu den elementaren mathematischen Kenntnissen und werden bereits in <a href="Euklids_Elemente" class="mw-redirect" title="Euklids Elemente">Euklids Elementen</a> behandelt.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> Die Dreisatzregel wird (ohne Begründung) als <i>regula de tri</i> in den Rechenbüchern von <a href="Adam_Ries" title="Adam Ries">Adam Ries</a><sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> angegeben. Die Bezeichnung <i>Dreisatz</i> rührt her von den drei gegebenen, in die Rechnung <i>eingesetzten</i> (in altem Deutsch: „gesatzten“) Größen. Heutige deutsche Schulbücher deuten die Bezeichnung oft als das „Lösen in drei Sätzen“. In algebraischer Schreibweise handelt es sich bei der Dreisatzaufgabe um eine <a href="Quotient#Proportionen" title="Quotient">Verhältnisgleichung</a>:
</p>
<dl><dd><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a:b=c:x}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
<mo>:</mo>
<mi>b</mi>
<mo>=</mo>
<mi>c</mi>
<mo>:</mo>
<mi>x</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a:b=c:x}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e2c3e56fe2e1bfdc1429f3abebb9fcba767302ed.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:11.537ex; height:2.176ex;" alt="{\displaystyle a:b=c:x}" loading="lazy"></span></dd></dl>
<p>Durch Umstellen der Gleichung gewinnt man die Lösung <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x=c\cdot (b:a)}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mo>=</mo>
<mi>c</mi>
<mo>⋅<!-- ⋅ --></mo>
<mo stretchy="false">(</mo>
<mi>b</mi>
<mo>:</mo>
<mi>a</mi>
<mo stretchy="false">)</mo>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x=c\cdot (b:a)}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/4a9629bc53801ae366a1508767ff8a4f787f0df3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:13.088ex; height:2.843ex;" alt="{\displaystyle x=c\cdot (b:a)}" loading="lazy"></span>
(<a href="#Beispiel_2_(einfacher_und_umgekehrter_Dreisatz)">Beispiel 2a</a>).
</p>
<div class="mw-heading mw-heading2"><h2 id="Umgekehrter_Dreisatz">Umgekehrter Dreisatz</h2></div>
<ul><li>Es liegt eine Gesetzmäßigkeit der Art „Je weniger A, umso mehr B.“ vor (<a href="Antiproportionalit%C3%A4t" class="mw-redirect" title="Antiproportionalität">indirekte Proportionalität</a>, <a href="#Beispiel_2_(einfacher_und_umgekehrter_Dreisatz)">Beispiel 2b</a>): Beim Halbieren (Dritteln, …) von A wird B verdoppelt (verdreifacht, …).</li>
<li>Dabei ergeben <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ffd2487510aa438433a2579450ab2b3d557e5edc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.23ex; height:1.676ex;" alt="{\displaystyle a}" loading="lazy"></span> Einheiten einer Größe A mit <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle b}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>b</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle b}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f11423fbb2e967f986e36804a8ae4271734917c3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:0.998ex; height:2.176ex;" alt="{\displaystyle b}" loading="lazy"></span> Einheiten einer Größe B ein konstantes Produkt.</li>
<li>Gefragt wird nach der Anzahl <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/87f9e315fd7e2ba406057a97300593c4802b53e4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.33ex; height:1.676ex;" alt="{\displaystyle x}" loading="lazy"></span> Einheiten der Größe B, die mit <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>c</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/86a67b81c2de995bd608d5b2df50cd8cd7d92455.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.007ex; height:1.676ex;" alt="{\displaystyle c}" loading="lazy"></span> Einheiten von A dasselbe Produkt ergeben: <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a\cdot b=c\cdot x}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
<mo>⋅<!-- ⋅ --></mo>
<mi>b</mi>
<mo>=</mo>
<mi>c</mi>
<mo>⋅<!-- ⋅ --></mo>
<mi>x</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a\cdot b=c\cdot x}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/5680634cd6625eecf11c72af6fb68687ee4db223.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:11.021ex; height:2.176ex;" alt="{\displaystyle a\cdot b=c\cdot x}" loading="lazy"></span>.</li></ul>
<p>In beiden Spalten der Tabelle werden entgegengesetzte Rechenoperationen ausgeführt:
</p>
<table class="wikitable" style="text-align:center;">
<tbody><tr>
<td><i>Rechne:</i></td>
<td>Größe A</td>
<td>Größe B</td>
<td><i>Rechne:</i>
</td></tr>
<tr>
<td><i>durch</i> <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ffd2487510aa438433a2579450ab2b3d557e5edc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.23ex; height:1.676ex;" alt="{\displaystyle a}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ffd2487510aa438433a2579450ab2b3d557e5edc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.23ex; height:1.676ex;" alt="{\displaystyle a}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle b}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>b</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle b}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/f11423fbb2e967f986e36804a8ae4271734917c3.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:0.998ex; height:2.176ex;" alt="{\displaystyle b}" loading="lazy"></span></td>
<td><i>mal</i> <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/ffd2487510aa438433a2579450ab2b3d557e5edc.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.23ex; height:1.676ex;" alt="{\displaystyle a}" loading="lazy"></span>
</td></tr>
<tr>
<td><i>mal</i> <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>c</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/86a67b81c2de995bd608d5b2df50cd8cd7d92455.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.007ex; height:1.676ex;" alt="{\displaystyle c}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle 1}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mn>1</mn>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle 1}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/92d98b82a3778f043108d4e20960a9193df57cbf.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.162ex; height:2.176ex;" alt="{\displaystyle 1}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a\cdot b}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
<mo>⋅<!-- ⋅ --></mo>
<mi>b</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a\cdot b}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/620419d3ed53abc98659a5fc0f3a5eb6177830ae.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:3.906ex; height:2.176ex;" alt="{\displaystyle a\cdot b}" loading="lazy"></span></td>
<td><i>durch</i> <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>c</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/86a67b81c2de995bd608d5b2df50cd8cd7d92455.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.007ex; height:1.676ex;" alt="{\displaystyle c}" loading="lazy"></span>
</td></tr>
<tr>
<td></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>c</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/86a67b81c2de995bd608d5b2df50cd8cd7d92455.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:1.007ex; height:1.676ex;" alt="{\displaystyle c}" loading="lazy"></span></td>
<td><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a\cdot b/c}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>a</mi>
<mo>⋅<!-- ⋅ --></mo>
<mi>b</mi>
<mrow class="MJX-TeXAtom-ORD">
<mo>/</mo>
</mrow>
<mi>c</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a\cdot b/c}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/d8e91b0ef3b71b2ec73c8f3f361bced1ffe4c869.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:6.076ex; height:2.843ex;" alt="{\displaystyle a\cdot b/c}" loading="lazy"></span></td>
<td>
</td></tr></tbody></table>
<div class="mw-heading mw-heading2"><h2 id="Verallgemeinerter_Dreisatz">Verallgemeinerter Dreisatz</h2></div>
<p>Beim <i>verallgemeinerten Dreisatz</i> (auch <i>zusammengesetzer Dreisatz</i>) gehen Produkte mehrerer Größen in das Verhältnis ein
(vgl. <a href="#Beispiel_3_(verallgemeinerter_Dreisatz)">Beispiel 3</a>).
</p><p>Ausgehend von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a_{1}\cdot b_{1}\cdot c_{1}\ \mathrel {\widehat {=}} \ d_{1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>a</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>b</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mtext> </mtext>
<mrow class="MJX-TeXAtom-REL">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mo>=</mo>
<mo>^<!-- ^ --></mo>
</mover>
</mrow>
</mrow>
<mtext> </mtext>
<msub>
<mi>d</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a_{1}\cdot b_{1}\cdot c_{1}\ \mathrel {\widehat {=}} \ d_{1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/4b0d3f4c33c90d66e044841514a3b0c734462600.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:16.278ex; height:2.676ex;" alt="{\displaystyle a_{1}\cdot b_{1}\cdot c_{1}\ \mathrel {\widehat {=}} \ d_{1}}" loading="lazy"></span>
kann man auf zwei Wegen die Lösung des Problems
<span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a_{2}\cdot b_{2}\cdot c_{2}\ \mathrel {\widehat {=}} \ x}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>a</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>b</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msub>
<mtext> </mtext>
<mrow class="MJX-TeXAtom-REL">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mo>=</mo>
<mo>^<!-- ^ --></mo>
</mover>
</mrow>
</mrow>
<mtext> </mtext>
<mi>x</mi>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a_{2}\cdot b_{2}\cdot c_{2}\ \mathrel {\widehat {=}} \ x}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/4ef25d51a4331c95a4b953bea1970b6568dad1f4.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:15.345ex; height:2.676ex;" alt="{\displaystyle a_{2}\cdot b_{2}\cdot c_{2}\ \mathrel {\widehat {=}} \ x}" loading="lazy"></span>
bestimmen.
Der einfache Dreisatz ist mehrfach anzuwenden
(man geht zuerst von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a_{1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>a</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a_{1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/bbf42ecda092975c9c69dae84e16182ba5fe2e07.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.284ex; height:2.009ex;" alt="{\displaystyle a_{1}}" loading="lazy"></span> zu <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a_{2}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>a</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a_{2}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/270580da7333505d9b73697417d0543c43c98b9f.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.284ex; height:2.009ex;" alt="{\displaystyle a_{2}}" loading="lazy"></span> über,
dann von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle b_{1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>b</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle b_{1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/9af2720c91be489f57ecde4bb651b95e113d0144.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.052ex; height:2.509ex;" alt="{\displaystyle b_{1}}" loading="lazy"></span> zu <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle b_{2}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>b</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle b_{2}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/2530a260ad35bf21ee61f1f4d6493ae0474f6068.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.052ex; height:2.509ex;" alt="{\displaystyle b_{2}}" loading="lazy"></span>
und schließlich von <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c_{1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c_{1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/77b7dc6d279091d354e0b90889b463bfa7eb7247.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.061ex; height:2.009ex;" alt="{\displaystyle c_{1}}" loading="lazy"></span> zu <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle c_{2}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle c_{2}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/0b30ba1b247fb8d334580cec68561e749d24aff2.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:2.061ex; height:2.009ex;" alt="{\displaystyle c_{2}}" loading="lazy"></span>).
Alternativ können alle Schritte auch gleichzeitig ausgeführt werden:
</p>
<ol><li><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a_{1}\cdot b_{1}\cdot c_{1}\ \mathrel {\widehat {=}} \ d_{1}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<msub>
<mi>a</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>b</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mtext> </mtext>
<mrow class="MJX-TeXAtom-REL">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mo>=</mo>
<mo>^<!-- ^ --></mo>
</mover>
</mrow>
</mrow>
<mtext> </mtext>
<msub>
<mi>d</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle a_{1}\cdot b_{1}\cdot c_{1}\ \mathrel {\widehat {=}} \ d_{1}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/4b0d3f4c33c90d66e044841514a3b0c734462600.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:16.278ex; height:2.676ex;" alt="{\displaystyle a_{1}\cdot b_{1}\cdot c_{1}\ \mathrel {\widehat {=}} \ d_{1}}" loading="lazy"></span></li>
<li><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle 1\ \mathrel {\widehat {=}} \ {\frac {d_{1}}{a_{1}\cdot b_{1}\cdot c_{1}}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mn>1</mn>
<mtext> </mtext>
<mrow class="MJX-TeXAtom-REL">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mo>=</mo>
<mo>^<!-- ^ --></mo>
</mover>
</mrow>
</mrow>
<mtext> </mtext>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<msub>
<mi>d</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mrow>
<msub>
<mi>a</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>b</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
</mrow>
</mfrac>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle 1\ \mathrel {\widehat {=}} \ {\frac {d_{1}}{a_{1}\cdot b_{1}\cdot c_{1}}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/e1557eb19d0ccdd610990d26cfd61f7798c684e7.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.338ex; width:16.013ex; height:5.843ex;" alt="{\displaystyle 1\ \mathrel {\widehat {=}} \ {\frac {d_{1}}{a_{1}\cdot b_{1}\cdot c_{1}}}}" loading="lazy"></span></li>
<li><span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle x\ \mathrel {\widehat {=}} \ {\frac {d_{1}\cdot a_{2}\cdot b_{2}\cdot c_{2}}{a_{1}\cdot b_{1}\cdot c_{1}}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mi>x</mi>
<mtext> </mtext>
<mrow class="MJX-TeXAtom-REL">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mo>=</mo>
<mo>^<!-- ^ --></mo>
</mover>
</mrow>
</mrow>
<mtext> </mtext>
<mrow class="MJX-TeXAtom-ORD">
<mfrac>
<mrow>
<msub>
<mi>d</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>a</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>b</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>2</mn>
</mrow>
</msub>
</mrow>
<mrow>
<msub>
<mi>a</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>b</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
<mo>⋅<!-- ⋅ --></mo>
<msub>
<mi>c</mi>
<mrow class="MJX-TeXAtom-ORD">
<mn>1</mn>
</mrow>
</msub>
</mrow>
</mfrac>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle x\ \mathrel {\widehat {=}} \ {\frac {d_{1}\cdot a_{2}\cdot b_{2}\cdot c_{2}}{a_{1}\cdot b_{1}\cdot c_{1}}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/208cfbb43d66080ac0fd533b97e5d3a55f0c241c.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.338ex; width:20.123ex; height:5.843ex;" alt="{\displaystyle x\ \mathrel {\widehat {=}} \ {\frac {d_{1}\cdot a_{2}\cdot b_{2}\cdot c_{2}}{a_{1}\cdot b_{1}\cdot c_{1}}}}" loading="lazy"></span></li></ol>
<p>Aufgaben hierzu finden sich auch unter der Überschrift <i>Fünfsatz</i>, weil aus fünf Größen eine sechste zu bestimmen ist.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup>
</p>
<div class="mw-heading mw-heading2"><h2 id="Beispiele">Beispiele</h2></div>
<div class="mw-heading mw-heading3"><h3 id="Beispiel_1">Beispiel 1</h3></div>
<p>In 3 Stunden legt ein Fahrzeug bei konstanter Geschwindigkeit 240 km zurück. Wie weit kommt es in 7 Stunden?
Es gilt:
</p>
<dl><dd><i>3 zu 240</i> verhält sich wie <i>7 zu „x“</i></dd></dl>
<p>Rechnung in Tabellenform:
</p>
<table class="wikitable" style="text-align:center;">
<tbody><tr>
<td></td>
<td>Zeit in h</td>
<td>Strecke in km</td>
<td><i>Rechne:</i>
</td></tr>
<tr>
<td>1.</td>
<td>3</td>
<td>240</td>
<td>: 3
</td></tr>
<tr>
<td>2.</td>
<td>1</td>
<td>80</td>
<td>· 7
</td></tr>
<tr>
<td>3.</td>
<td>7</td>
<td><b>560</b></td>
<td>
</td></tr></tbody></table>
<p>Lösung: In 7 Stunden kommt das Fahrzeug 560 km weit.
</p>
<div class="mw-heading mw-heading3"><h3 id="Beispiel_2_(einfacher_und_umgekehrter_Dreisatz)"><span id="Beispiel_2_.28einfacher_und_umgekehrter_Dreisatz.29"></span>Beispiel 2 (einfacher und umgekehrter Dreisatz)</h3></div>
<p>Die folgenden Beispiele haben dieselben Zahlen, jedoch unterschiedliche Verhältnisse. Im ersten Beispiel beziehen sich die Mengenangaben auf einen festen Zeitraum (<i>ein Arbeitstag</i>). Im zweiten Beispiel beziehen sich die Zeitangaben auf eine feste Mengenangabe (<i>eine bestimmte Menge Abraum</i>).
</p><p>a) 21 Lastwagen transportieren 35 Tonnen Abraum an einem Arbeitstag. Wie viel Tonnen Abraum schaffen in derselben Zeit 15 Lastwagen?
</p>
<ul><li>21 Lkw <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\mathrel {\widehat {=}}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-REL">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mo>=</mo>
<mo>^<!-- ^ --></mo>
</mover>
</mrow>
</mrow>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {\mathrel {\widehat {=}}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/eca337e63214191683c3ce616a1a60ac336ba1ef.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: 0.307ex; margin-bottom: -0.645ex; width:1.808ex; height:2.343ex;" alt="{\displaystyle \mathrel {\widehat {=}} }" loading="lazy"></span> 35 Tonnen</li>
<li>15 Lkw <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\mathrel {\widehat {=}}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-REL">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mo>=</mo>
<mo>^<!-- ^ --></mo>
</mover>
</mrow>
</mrow>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {\mathrel {\widehat {=}}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/eca337e63214191683c3ce616a1a60ac336ba1ef.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: 0.307ex; margin-bottom: -0.645ex; width:1.808ex; height:2.343ex;" alt="{\displaystyle \mathrel {\widehat {=}} }" loading="lazy"></span> x Tonnen</li>
<li>x = 15 · 35 / 21 = 25, also 25 Tonnen.</li></ul>
<p>b) 21 Lastwagen benötigen 35 Tage für den Abtransport einer bestimmten Menge Abraum. Wie viel Zeit benötigen hierfür 15 Lastwagen?
</p>
<ul><li>21 Lkw <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\mathrel {\widehat {=}}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-REL">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mo>=</mo>
<mo>^<!-- ^ --></mo>
</mover>
</mrow>
</mrow>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {\mathrel {\widehat {=}}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/eca337e63214191683c3ce616a1a60ac336ba1ef.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: 0.307ex; margin-bottom: -0.645ex; width:1.808ex; height:2.343ex;" alt="{\displaystyle \mathrel {\widehat {=}} }" loading="lazy"></span> 35 Tage</li>
<li>15 Lkw <span class="mwe-math-element mwe-math-element-inline"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\mathrel {\widehat {=}}}}">
<semantics>
<mrow class="MJX-TeXAtom-ORD">
<mstyle displaystyle="true" scriptlevel="0">
<mrow class="MJX-TeXAtom-ORD">
<mrow class="MJX-TeXAtom-REL">
<mrow class="MJX-TeXAtom-ORD">
<mover>
<mo>=</mo>
<mo>^<!-- ^ --></mo>
</mover>
</mrow>
</mrow>
</mrow>
</mstyle>
</mrow>
<annotation encoding="application/x-tex">{\displaystyle {\mathrel {\widehat {=}}}}</annotation>
</semantics>
</math></span><img src="./_assets_/eb734a37dd21ce173a46342d1cc64c92/eca337e63214191683c3ce616a1a60ac336ba1ef.svg" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: 0.307ex; margin-bottom: -0.645ex; width:1.808ex; height:2.343ex;" alt="{\displaystyle \mathrel {\widehat {=}} }" loading="lazy"></span> x Tage</li>
<li>x = 35 · 21 / 15 = 49, also 49 Tage.</li></ul>
<div class="mw-heading mw-heading3"><h3 id="Beispiel_3_(verallgemeinerter_Dreisatz)"><span id="Beispiel_3_.28verallgemeinerter_Dreisatz.29"></span>Beispiel 3 (verallgemeinerter Dreisatz)</h3></div>
<p>2 Kühe fressen an einem Tag 48 kg Gras. Wie viel kg Gras fressen 5 Kühe in 6 Stunden?
</p>
<ol><li>2 Kühe fressen in 24 h 48 kg Gras</li>
<li>1 Kuh frisst in 1 h 1 kg Gras</li>
<li>5 Kühe fressen in 6 h 30 kg Gras</li></ol>
<p>unter der Annahme, dass die Kühe über die ganze Zeit gleichmäßig viel Gras fressen.
</p>
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<ul><li><a rel="nofollow" class="external text" href="https://portal.dnb.de/opac.htm?method=simpleSearch&query=4207136-7">Literatur von und über Dreisatz</a> im Katalog der <a href="Deutsche_Nationalbibliothek" title="Deutsche Nationalbibliothek">Deutschen Nationalbibliothek</a></li>
<li><a rel="nofollow" class="external text" href="http://www.schule.suedtirol.it/blikk/angebote/PRIMARMATHE/ma5000.htm">Pädagogisches Institut der deutschen Sprachgruppe Bozen</a></li>
<li><i><a rel="nofollow" class="external text" href="https://de.serlo.org/1769">Dreisatz</a>.</i> In: <i>Serlo</i>.</li></ul>
<div class="mw-heading mw-heading2"><h2 id="Einzelnachweise">Einzelnachweise</h2></div>
<ol class="references">
<li id="cite_note-1"><span class="mw-cite-backlink"><a href="#cite_ref-1">↑</a></span> <span class="reference-text"><cite style="font-style:italic">Regeldetri</cite>. In: <cite style="font-style:italic"><a href="Meyers_Konversations-Lexikon" title="Meyers Konversations-Lexikon">Meyers Großes Konversations-Lexikon</a></cite>. 6. Auflage. <span style="white-space:nowrap">Band<span style="display:inline-block;width:.2em"> </span>16</span>: <i>Plaketten–Rinteln</i>. Bibliographisches Institut, Leipzig / Wien 1908, <span style="white-space:nowrap">S.<span style="display:inline-block;width:.2em"> </span>698</span> (<a rel="nofollow" class="external text" href="http://www.zeno.org/nid/20007329512">Digitalisat.</a> <a href="Zeno.org" title="Zeno.org">zeno.org</a>).<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rfr_id=info:sid/de.wikipedia.org:Dreisatz&rft.atitle=Regeldetri&rft.btitle=Meyers+Gro%C3%9Fes+Konversations-Lexikon&rft.date=1908&rft.edition=6.&rft.genre=book&rft.pages=698&rft.place=Leipzig+%2F+Wien&rft.pub=Bibliographisches+Institut&rft.volume=Band+16%3A+Plaketten-Rinteln" style="display:none"> </span></span>
</li>
<li id="cite_note-2"><span class="mw-cite-backlink"><a href="#cite_ref-2">↑</a></span> <span class="reference-text"><cite style="font-style:italic">Regel Detri</cite>. In: <a href="Friedrich_Arnold_Brockhaus" title="Friedrich Arnold Brockhaus">Brockhaus</a> (Hrsg.): <cite style="font-style:italic"><a href="Brockhaus_Enzyklop%C3%A4die#„Die_kleinen_Schwestern“" title="Brockhaus Enzyklopädie">Conversations-Lexikon oder kurzgefaßtes Handwörterbuch</a></cite>. 1. Auflage. <span style="white-space:nowrap">Band<span style="display:inline-block;width:.2em"> </span>4</span>: <i>R</i>. Kunst- und Industrie-Comptoir, Amsterdam 1809, <span style="white-space:nowrap">S.<span style="display:inline-block;width:.2em"> </span>115–118</span> (<a rel="nofollow" class="external text" href="http://www.zeno.org/nid/20000767042">Digitalisat.</a> <a href="Zeno.org" title="Zeno.org">zeno.org</a>).<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rfr_id=info:sid/de.wikipedia.org:Dreisatz&rft.atitle=Regel+Detri&rft.btitle=Conversations-Lexikon+oder+kurzgefa%C3%9Ftes+Handw%C3%B6rterbuch&rft.date=1809&rft.edition=1.&rft.genre=book&rft.pages=115-118&rft.place=Amsterdam&rft.pub=Kunst-+und+Industrie-Comptoir&rft.volume=Band+4%3A+R" style="display:none"> </span></span>
</li>
<li id="cite_note-3"><span class="mw-cite-backlink"><a href="#cite_ref-3">↑</a></span> <span class="reference-text"><cite style="font-style:italic">Regula de Tri</cite>. In: <cite style="font-style:italic"><a href="Herders_Conversations-Lexikon" title="Herders Conversations-Lexikon">Herders Conversations-Lexikon</a></cite>. 1. Auflage. <span style="white-space:nowrap">Band<span style="display:inline-block;width:.2em"> </span>4</span>: <i>Lindenbrug – Ryut</i>. Herder, Freiburg im Breisgau 1856, <span style="white-space:nowrap">S.<span style="display:inline-block;width:.2em"> </span>689</span> (<a rel="nofollow" class="external text" href="http://www.zeno.org/nid/20003488802">Digitalisat.</a> <a href="Zeno.org" title="Zeno.org">zeno.org</a>).<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rfr_id=info:sid/de.wikipedia.org:Dreisatz&rft.atitle=Regula+de+Tri&rft.btitle=Herders+Conversations-Lexikon&rft.date=1856&rft.edition=1.&rft.genre=book&rft.pages=689&rft.place=Freiburg+im+Breisgau&rft.pub=Herder&rft.volume=Band+4%3A+Lindenbrug+-+Ryut" style="display:none"> </span></span>
</li>
<li id="cite_note-4"><span class="mw-cite-backlink"><a href="#cite_ref-4">↑</a></span> <span class="reference-text"><cite style="font-style:italic">Goldene Regel</cite>. In: <a href="Heinrich_August_Pierer" title="Heinrich August Pierer">Heinrich August Pierer</a>, <a href="Julius_L%C3%B6be" title="Julius Löbe">Julius Löbe</a> (Hrsg.): <cite style="font-style:italic"><a href="Universal-Lexikon_der_Gegenwart_und_Vergangenheit" title="Universal-Lexikon der Gegenwart und Vergangenheit">Universal-Lexikon der Gegenwart und Vergangenheit</a></cite>. 4. Auflage. <span style="white-space:nowrap">Band<span style="display:inline-block;width:.2em"> </span>7</span>: <i>Gascognisches Meer–Hannok</i>. Altenburg 1859, <span style="white-space:nowrap">S.<span style="display:inline-block;width:.2em"> </span>450</span> (<a rel="nofollow" class="external text" href="http://www.zeno.org/nid/20010022651">Digitalisat.</a> <a href="Zeno.org" title="Zeno.org">zeno.org</a>).<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rfr_id=info:sid/de.wikipedia.org:Dreisatz&rft.atitle=Goldene+Regel&rft.btitle=Universal-Lexikon+der+Gegenwart+und+Vergangenheit&rft.date=1859&rft.edition=4.&rft.genre=book&rft.pages=450&rft.place=Altenburg&rft.volume=Band+7%3A+Gascognisches+Meer-Hannok" style="display:none"> </span></span>
</li>
<li id="cite_note-5"><span class="mw-cite-backlink"><a href="#cite_ref-5">↑</a></span> <span class="reference-text">Euklid: <i>Die Elemente</i>. II. Teil. Buch V und VI. Ostwalds Klassiker der exakten Wissenschaften. <a href="Clemens_Thaer" title="Clemens Thaer">Clemens Thaer</a> (Hrsg.). Akademische Verlagsgesellschaft, Leipzig 1933.</span>
</li>
<li id="cite_note-6"><span class="mw-cite-backlink"><a href="#cite_ref-6">↑</a></span> <span class="reference-text">Adam Ries(e): <i>Rechnung auf Linien und Federn</i> … anno 1532.
114. Auflage. Magistrat der Stadt Erfurt, 1991, Pag. Biii.</span>
</li>
<li id="cite_note-7"><span class="mw-cite-backlink"><a href="#cite_ref-7">↑</a></span> <span class="reference-text">Lat. <i>regula quinque</i>. Vgl. etwa <a href="Johannes_Tropfke" title="Johannes Tropfke">Johannes Tropfke</a>: <i>Geschichte der Elementarmathematik</i>. Band 1: <i>Arithmetik und Algebra</i>. Vollständig neu bearbeitet von Kurt Vogel, Karin Reich, Helmuth Gericke. de Gruyter, Berlin und New York, 4. Auflage 1980, S. 360–362, 541.</span>
</li>
</ol>
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