Question

2. Convert the following decimal numbers to the 10’s complement:

a. 65                   

b. 327                   

c. 7643        

d. Perform subtraction using 10’s complement on 432-567

Answer 1

a)
65
1)  subtract from 99
    99 - 65 = 34
2)  add 1
34 + 1 = 35
Answer: 35

b)
327
1)  subtract from 999
    999 - 327 = 672
2)  add 1
672 + 1 = 673
Answer: 673

c)
7643
1)  subtract from 9999
    9999 - 7643 = 2356
2)  add 1
2356 + 1 = 2357
Answer: 2357

d)
432-567
convert -567 to 10's complement
567
1)  subtract from 999
    999 - 567 = 432
2)  add 1
432 + 1 = 433

432-567 = 432+433
432
433
---
865
---
since left most digit is 8. convert this to 10's complement again
999
865
---
134
---
add 1
134+1 = 135
Answer: -135