Opposite number

Opposite number or additive inverse of any number (n) is a number which, if added to n, results in 0, the identity element of addition. The opposite number for n is written as −n. For example, −7 is opposite to 7, because with $-\!7+7=0$. You can say that the opposite number of a number, is the negative version of the positive number. This is what the opposite of 7 is or the opposite of -7.