Computation speeds have increased dramatically during the past three decades resulting from the development of various technologies. The execution speed of an arithmetic operation is a function of two factors. The first is the circuit technology and the second is the used algorithm. Simulation of a Full Adder (FA) and 16-bit adder are represented in this paper. Ripple Carry Adder (RCA) and Skip Carry Adder (SCA) are used to simulated 16-bit adder. SCA is simulated for different structures such as 2, 4 and 8-blocks. Simulation results show that SCA is faster than RCA. Furthermore, 8-block SCA is faster than 4-block SCA and 4-block SCA is faster than 2-block SCA too.