Perform subtraction on the given unsigned numbers using the 10’s complement of the subtrahend. Where the result should be negative, find its 10’s complement and affix a minus sign. Verify your answers.
(a) 4,637 - 2,579 (b) 125 - 1,800
(c) 2,043 - 4,361 (d) 1,631 - 745
1.17 Ans: (a) 4637 – 2579
10’s complement of 2579 is 9999 - 2579 = 7420 + 1
= 7421
7421 + 4637 = 12058
Here 1 is carry, the result should be positive and by removing it 2058 is
the result.
(b) 125 -1800
10’s complement of 1800 is 9999 – 1800 = 8199 + 1
= 8200
125+8200 = 8325
Here there is no carry, the result should be negative so negative sign to
10’s complement of 8325 = 10,000 – 8325
= - 1675.
(c) 2043 - 4361
10’s complement of 4361 is 10,000 - 4361
=5639
2043 + 5639 = 7682
Here there is no carry, the result should be negative so negative sign to 10’s
complement of 7682 = 10,000 - 7682
= - 2318.
(d) 1631 - 745
10’s complement of 745 is 10,000 – 745
= 9255
1631+9255 = 10,886
Here there is carry 1, the result should be positive and by removing it 886 is
the result.