For computer arithmatic we use binary number system. The binary number system uses two symbols to represent the number and these two symbols are 0 and 1.

The binary number system is said to be of base 2 or radix 2, because it uses two digits and the coefficients are multiplied by power of 2.

The binary number 110011 represents the quantity equal to:

                        (in decimal)

We can use binary number system for computer arithmatic.