10. Addition of two 2's complement integers

• Addition rules of two 2's complement integers are quite simple:

  1. If two numbers with opposite signs are added, the result is zero.

  2. Also, representation of value+1 equals to the representation of value plus representation of 1 .

  3. Addition of positive numbers mirrors addition of decimal numbers, that is,

     • if a column generates a carry, it is added to the column immediately to the left.

  4. If overflow occurs, last carry out is ignored (thrown away.)