two's complement

Wiktionary

1. n. computing The number obtained by complementing every bit of a given number and adding one. A number and its complement add to 2n, where n is the word size of the machine.
2. n. computing The convention by which bit patterns with high bit 0 represent positive numbers from 0 to directly, while bit patterns with high bit 1 represent negative numbers from -1 to , n. being the word size of the machine, and the numeric complement of a number is its two's complement.