The division sign resembles a dash or double dash with a dot above and a dot below (÷). It is equivalent to the words "divided by." This symbol is found mainly in arithmetic texts at the elementary-school level. It is rarely used by professional or academic mathematicians, scientists, or engineers.
Mathematically, the division sign is equivalent to the forward slash. Thus, for example, 4 ÷ 5 = 4/5 = 0.8, and -100 ÷ 10 = -100/10 = -10. In general, for any real number x and any nonzero real number y , the following is always true:
x ÷ y = x / y
The division sign is also mathematically equivalent to the ratio symbol, customarily denoted by a colon (:) and read "is to." Thus, for any real number x and any nonzero real number y , this equation holds:
x ÷ y = x : y
On most IBM-compatible computers, the division symbol can be generated by activating the NUM LOCK function, holding down the ALT key, and entering 246 on the numeric keypad located at the right-hand end of the keyboard. The division sign appears when the ALT key is released. This technique works in most word processors, and even in some graphics and DOS programs.
Also see Mathematical Symbols .