# Opposite number

In mathematics, the opposite or additive inverse of a number ${\displaystyle k}$ is a number ${\displaystyle n}$ which, when added to ${\displaystyle k}$, results in 0. The opposite of ${\displaystyle a}$ is ${\displaystyle -a}$.[1][2] For example, −7 is the opposite of 7, because ${\displaystyle 7+-7=0}$.