# What is a reciprocal of a number?

The reciprocal of a number, $a$, is a number, $b$ such that
$a \times b = 1$
For Real numbers, other than 0, the reciprocal of $a$ is $\frac{1}{a}$.
(The number $0$ does not have a reciprocal because $0 \times b = 1$ has no solution. $0 \times n = 0$ for all real and complex $n$.)