The adder is a device that can add binary numbers, it can use for the addition of binary numbers, binary code decimal, address decoding and table index calculation, There are two types of adders.

- Half Adder
- Full Adder

Half adder:

A half adder is a computational circuit which is used to add two binary numbers, it is the made by one XOR and one AND gate, it has two input (A, B) and two output (sum, carry).