Division sign

The division sign (÷) is a symbol consisting of a short horizontal line with a dot above and another dot below, used in Anglophone countries to indicate mathematical division. However, this usage, though widespread in some countries, is not universal; it is used for other purposes in other countries and its use to denote division is not recommended in the ISO 80000-2 standard for mathematical notation.[1]

÷
Division sign
In UnicodeU+00F7 ÷ DIVISION SIGN (÷, ÷)
Different from
Different fromU+2052 COMMERCIAL MINUS SIGN
U+002B + PLUS SIGN
U+2020 DAGGER
U+034B ͋ COMBINING HOMOTHETIC ABOVE
Related
See alsoU+00D7 × MULTIPLICATION SIGN

In mathematicsEdit

 
The symbol does not represent division in every country. Here it is being used as a minus sign (not as a division sign) in an excerpt from an official Norwegian trading statement form called «Næringsoppgave 1» for the taxation year 2010.

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.[2] Some near-contemporaries believed that John Pell, who edited the book, may have been responsible for this use of the symbol.[2] Other symbols for division include the slash or solidus /, the colon :, and the fraction bar (the horizontal bar in a vertical fraction).[3][4] 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.[1]

In Italy, Poland and Russia, the ÷ sign was sometimes used to denote a range of values, and in Scandinavian countries it was used as a negation sign.[5]

Historically, an oblique form of the obelus, (commercial minus sign), has also been used to represent subtraction in Northern Europe; such usage continued in some parts of Europe, including Norway and—until fairly recently—Denmark.[citation needed]

In computer systemsEdit

EncodingEdit

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.[6] In HTML, it can be encoded as ÷ or ÷ (at HTML level 3.2), or as ÷.

Keyboard entryEdit

In Microsoft Windows, this division sign is produced with Alt+0247 (or 246 with no zero) on the number pad, or by pressing Alt Gr+⇧ Shift++ when an appropriate keyboard layout is in use. In classic Mac OS and macOS, it is produced with ⌥ Option+/.

On UNIX-based systems using Screen or X with a Compose key enabled, it can be produced by composing : (colon) and - (hyphen/minus). It may also be produced using its Unicode code-point (F7), by pressing Control+⇧ Shift+u f7space.

In LaTeX, the division sign is obtained by the command \div.

In Chrome OS (with International/Extended keyboard setting), the division sign is obtained by pressing AltGr+⇧ Shift+>. Otherwise, the Unix-style methods may be used.

See alsoEdit

NotesEdit

  1. ^ a b ISO 80000-2, Section 9 "Operations", 2-9.6
  2. ^ a b 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". The Unicode® Standard: Version 10.0 – Core Specification (PDF). Unicode Consortium. June 2017. p. 280, Obelus.
  6. ^ Korpela, Jukka (2006), Unicode Explained: Internationalize documents, programs, and web sites, O'Reilly Media, Inc., p. 397, ISBN 9780596101213

External linksEdit

  The dictionary definition of division sign at Wiktionary