Division sign

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 used as a negation sign.

The same symbol has been used to represent subtraction in north-eastern Europe: the Unicode Consortium has allocated a separate code point, for this usage uniquely;  the exact form of the symbol displayed is typeface (font) dependent.

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 &divide; or &#xF7; (at HTML level 3.2), or as &#247;.

Unicode provides various division symbols:

Keyboard entry
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 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.

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. Otherwise, the Unix-style methods may be used.