Fulladder using Half adder

Truth Table:

A	B	Cin	Sout	C out
0	0	0	0	0
0	0	1	1	0
0	1	0	1	0
0	1	1	0	1
1	0	0	1	0
1	0	1	0	1
1	1	0	0	1
1	1	1	1	1

Equations:

Sout= A^B^Cin

Cout= A.B+B.Cin+Cin.A

Circuit Diagram: 

Explanation:

In the above circuit A and B are added using half adder. Sum of A and B given to the 2nd half adder and added with Cin. Carry of both the halfadders are  given to OR gate which gives Carry Out.