Question

How do you calculate the additive inverse of a binary number?

Answer 1

Take the `1`'s complement and add `1`

Explanation:

The exact form depends on the word size you are using for your binary numbers.

A `1`'s complement is formed by flipping every bit - i.e. apply the "not" operator to every bit.

For example, with a `32` bit word, the `1`'s complement of `10100` is:

`1111` `1111` `1111` `1111` `1111` `1111` `1110` `1011`

Then add `1` to get:

`1111` `1111` `1111` `1111` `1111` `1111` `1110` `1100`