Two's Complement/Complementary Representation

•A negative number is represented by the two’s complement of the corresponding positive number. •As a result, subtraction can be implemented using addition, so no subtraction (hardware or software) is required. •There is nothing magical. Consider two decimal operations:

  8 - 3   = 5

  8 + (10  - 3) = 8 + 7   =15

  The results are the same if we discard the leftmost digit (i.e. 1) in the second result (so 8 – 3 can be computed using 8 + 7!)

•Here, 7 is called the ten’s complement of 3 in terms of 7+3 = 10. So subtracting a number can be performed by adding the number’s complement. No need to…