https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&feedformat=atom&user=Copernicium 2026-05-24T09:17:06Z User contributions MediaWiki 1.30.0 https://www.explainxkcd.com/wiki/index.php?title=2687:_Division_Notation&diff=297059 2022-10-19T22:58:30Z

<p>Copernicium: /* Explanation */</p> <hr /> <div>{{comic<br /> | number = 2687<br /> | date = October 19, 2022<br /> | title = Division Notation<br /> | image = division_notation_2x.png<br /> | imagesize = 235x310px<br /> | noexpand = true<br /> | titletext = Science tip: Scientists hardly ever use the two-dot division sign, and when they do it often doesn't even mean division, but they still get REALLY mad when you repurpose it to write stuff like SALE! ALL SHOES 30÷ OFF!<br /> }}<br /> <br /> ==Explanation==<br /> {{incomplete|Created by a GROUP OF SCHOOLCHILDREN DIVIDED AMONGST THEMSELVES - Please change this comment when editing this page. Do NOT delete this tag too soon.}}<br /> <br /> This comic pokes fun at some of the ways to write the division operation in math. In this comic, Randall has used A as the dividend (the number being divided) and B as the divisor (the number that A is divided by).<br /> The first two are respectively the division sign (÷) and long division symbol. (Note: the long division symbol is only used in English-speaking countries). These methods of division are often used by school children as the first ÷ is what people learn when first learning division, and the second long division symbol is usually the first type of long division learned (it's easier to do it visually on paper that way).<br /> <br /> The third line is the way the division is often written in code. The 4 standard operations in programming usually are +, -, *, /. This one was missing in the first version of the comic.<br /> <br /> The fourth notation is the way division is written in science, dividend on top line and divided on bottom line.<br /> <br /> The fifth notation uses a negative exponent. The exponent -1 has the same effect as dividing by the base. It can be used to keep an equation on 1 line.<br /> <br /> The final form of notation appears to be not a simple notation for division. Rather, it looks like a definition of a notion of division which is customized to a particular setting. This situation is likely to occur in abstract algebra, where one might have to define what &quot;division&quot; might mean for two elements of a mathematical object such as a group, ring, or magma. One example would be an object G, such that, for two elements A and B of G, &quot;A divided by B&quot; is defined as an element C such that CB=A, or alternatively as an element C such that BC=A. These definitions might differ if multiplication in G is not commutative. Furthermore, if such a C is not unique, a function F(A,B) might have to be chosen to select a unique value for &quot;A divided by B&quot; for each A and B. Thus, the F(A,B) in the comic might not even refer to a uniquely defined operation, but simply to the property of a function F(A,B) that is a valid division operation on G, given some definition of division.<br /> <br /> ==Transcript==<br /> {{incomplete transcript|Do NOT delete this tag too soon.}}<br /> A÷B and A⟌B both indicating schoolchild.<br /> <br /> A/B left to software engineer.<br /> <br /> A/B as in unicode ½ left to normal person or Unicode enthusiast.<br /> <br /> A over B left to scientist.<br /> <br /> AB^-1 left to fancy scientist.<br /> <br /> F(A, B) such that (text getting smaller) next to oh no, run.<br /> <br /> {{comic discussion}}</div>

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