Method : 10's complement subtraction steps :
1. At first, find 10's complement of the B(subtrahend).
2. Then add it to the A(minuend).
3. If the final carry over of the sum is 1, then it is dropped and the result is positive.
4. If there is no carry over, then 10's complement of the sum is the final result and it is negative.
1. Find Subtraction of 470 and 231 using 10's complement method
Here A = 470, B = 231.
Find A - B = ? using 10's complement
First find 10's complement of B = 231
Note : 10's complement of a number is 1 added to it's 9's complement number.
9's complement of 231 is
Now add 1 : 768 + 1 = 769
Now Add this 10's complement of B to A
Hints : (Move mouse over the steps for detail calculation highlight)
Step-1 `=0+9` `=9` `:.` Sum`=9` | Step-2 `=7+6` `=13` `:.` Sum`=3` and carry`=1` |
Step-3 `=1+4+7` `=12` `:.` Sum`=2` and carry`=1` | |
The left most bit of the result is called carry and it is ignored.
So answer is 239
2. Find Subtraction of 670 and 831 using 10's complement method
Here A = 670, B = 831.
Find A - B = ? using 10's complement
First find 10's complement of B = 831
Note : 10's complement of a number is 1 added to it's 9's complement number.
9's complement of 831 is
Now add 1 : 168 + 1 = 169
Now Add this 10's complement of B to A
Hints : (Move mouse over the steps for detail calculation highlight)
Step-1 `=0+9` `=9` `:.` Sum`=9` | Step-2 `=7+6` `=13` `:.` Sum`=3` and carry`=1` |
Step-3 `=1+6+1` `=8` `:.` Sum`=8` | |
Here there is no carry, answer is - (10's complement of the sum obtained 839)
Note : 10's complement of a number is 1 added to it's 9's complement number.
9's complement of 839 is
Now add 1 : 160 + 1 = 161
So answer is -161
This material is intended as a summary. Use your textbook for detail explanation.
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