Complements are used in the digital computers in order to simplify the subtraction operation and for logical manipulations.
The two types of complements are 1’s complement and 2’s complement.
1. 1’s complement:
The 1 ’s complement of a number is found by changing all 1’s to 0’s and all 0’s to 1’s. This is called as taking complement or 1’s complement. For example, 10101 is 01010 in 1’s complement.
2. 2’s complement:
The 2’s complement of binary number is obtained by adding 1 to the Least Significant Bit (LSB) of 1 ’s complement of the number. 2’s complement = 1’s complement + 1
For example, 10101(2) 1’s complement is 01010 and 01010 + 1 = 01011 is 2’s complement.
