Division sign (÷)

How to read it

OpenStax’s Prealgebra reads 12 ÷ 4 as “twelve divided by four” and gives the same division written as 12 / 4 and as a fraction. The sign is U+00F7, DIVISION SIGN; Unicode gives its other name, obelus.

Also searched as: ÷, division symbol, obelus.

÷ and the obelus of old manuscripts

Unicode notes that ÷ was “historically used as a punctuation mark to denote questionable passages in manuscripts”, and that it is sometimes used as a more visible hyphen. The dagger † (U+2020) has the old name obelisk.

Look-alikes

The commercial minus sign ⁒ (U+2052) looks similar and means minus: Unicode gives its German name, abzüglich, and Swedish ones, med avdrag av and piska. Division is also written with the division slash ∕ (U+2215) and the ratio sign ∶ (U+2236), and ∣ (U+2223) means “divides”.

÷ or : by country

Cajori wrote in 1928 that no symbols observed political boundaries as closely as ÷ and the colon did for division: ÷ belonged to Great Britain, the British dominions and the United States, and : to Continental Europe and Latin America.

When ÷ and × meet

Cajori also wrote that there was “at present no agreement” on which sign to take first in a term with both ÷ and ×. Miller quotes Wells and Hart’s First Year Algebra (1912) on doing multiplications and divisions from left to right, and records a textbook publisher in 2011 acknowledging that one of its expressions was ambiguous.