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The division sign (÷) is a mathematical symbol consisting of a short horizontal line with a dot above and another dot below, used in Anglophone countries to indicate the operation of division. This usage, though widespread in some countries, is not universal and the symbol has a different meaning in other countries. Its use to denote division is not recommended in the ISO 80000-2 standard for mathematical notation.

In mathematics

The obelus, a historical glyph consisting of a horizontal line with (or without) one or more dots, was first used as a symbol for division in 1659, in the algebra book Teutsche Algebra by Johann Rahn, although previous writers had used the same symbol for subtraction. Some near-contemporaries believed that John Pell, who edited the book, may have been responsible for this use of the symbol. Other symbols for division include the slash or solidus /, the colon :, and the fraction bar (the horizontal bar in a vertical fraction). The ISO 80000-2 standard for mathematical notation recommends only the solidus / or "fraction bar" for division, or the "colon" : for ratios; it says that the ÷ sign "should not be used" for division.

In Italy, Poland and Russia, the ÷ sign was sometimes used to denote a range of values, and in Scandinavian countries it was, and sometimes still is, used as a negation sign: the Unicode Consortium has allocated a separate code point, U+2052 ⁒ COMMERCIAL MINUS SIGN for this usage uniquely; the exact form of the symbol displayed is typeface (font) dependent.

In computer systems

Encoding

The symbol was assigned to code point 0xF7 in ISO 8859-1, as the "division sign". This encoding was transferred to Unicode as U+00F7. In HTML, it can be encoded as ÷ or ÷ (at HTML level 3.2), or as ÷.

Unicode provides various division symbols:

See also

• Plus and minus signs
• Multiplication sign

Notes

1. ^ ISO 80000-2, Section 9 "Operations", 2-9.6
2. ^ Cajori, Florian (1928). A history of mathematical notations. Vol. 1. Notations in Elementary Mathematics. The Open Court Company. pp. 242, 270–271. pp 270,271
3. Weisstein, Eric W. "Division". mathworld.wolfram.com. Retrieved 2020-08-26.
4. "Division". www.mathsisfun.com. Retrieved 2020-08-26.
5. "6. Writing Systems and Punctuation" (PDF). The Unicode® Standard: Version 10.0 – Core Specification. Unicode Consortium. June 2017. p. 280, Obelus.
6. Leif Halvard Silli. "Too narrowly defined: DIVISION SIGN & COLON". Unicode.org.
7. Leif Halvard Silli. "Commercial minus as italic variant of division sign in German and Scandinavian context". Unicode.org.
8. Korpela, Jukka (2006), Unicode Explained: Internationalize documents, programs, and web sites, O'Reilly Media, Inc., p. 397, ISBN 9780596101213
9. "Division symbol".

External links

• Jeff Miller: Earliest Uses of Various Mathematical Symbols
• Michael Quinion: Where our arithmetic symbols come from

The dictionary definition of division sign at Wiktionary

• Mathematical symbols
• Typographical symbols
• Division (mathematics)
• Ancient Greek punctuation