For 599 and 015, Find BCD Subtraction using 10's complement
Solution:
`599-015` BCD subtraction using `10's` complement
Steps for BCD subtraction using `10's` complement
For `A-B`
1. Take `10's` complement for B
2. Add it to A using BCD addition
3. If addition is invalid BCD then add 6
4. If carry then add it to the next bits
5. In final result, if carry is occured then it is ignored and if
there is no any carry over, then take `10's` complement of the result and it is negative.
1. Take `10's` complement for `015`
Note : 10's complement of a number is 1 added to it's 9's complement number.
Step-1: 9's complement of 015 is obtained by subtracting each digit from 9
Step-2: Now add 1 to the 9's complement to obtain the 10's complement :
984 + 1 = 985
2. Add `599` and `985` using BCD addition
| BCD code for 599 : | 0101 | 1001 | 1001 |
| BCD code for 985 : | 1001 | 1000 | 0101 |
|
| Addition : | 1110 | 10001 | 1110 |
| If Invalid BCD then add 6 : | 0110 | 0110 | 0110 |
|
| Addition : | 10100 | 10111 | 10100 |
|
| Remaining bits except carry : | 10100 | 0111 | 0100 |
| Carry : | 1 | 1 | |
|
| Addition : | 10101 | 1000 | 0100 |
| BCD value : | 15 | 8 | 4 |
The left most bit of the result is 1, called carry and it is ignored.
So final answer of BCD Subtraction is `584`
This material is intended as a summary. Use your textbook for detail explanation.
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