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.[1]
In mathematics
Plus and minuses. The obelus – or division sign – used as a variant of the minus 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]
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.[8] In HTML, it can be encoded as ÷ or ÷ (at HTML level 3.2), or as ÷.
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+uf7space.
In LaTeX, the division sign is obtained by the command \div.
In ChromeOS (with International/Extended keyboard setting), the division sign is obtained by pressing AltGr+⇧ Shift++. Otherwise, the Unix-style methods may be used.
