## Problem with 2’s complement: hard to find the negation of a number because it involves “adding 1”

## This leads to 1’s complement. In 1’s complement, instead of subtracting from 100, you subtract from 99. This means that in binary, you only need to invert the bits!

## The price to pay is that when we pass the 100 mark, we’ll be off by 1 (eg: -10 + 30 leads to 89 + 30 = 119. But we want 120!).

## So, every time you pass the 100 mark, you need to add an extra 1.

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