1. Subtraction can be performed using addition by taking the complement of the subtrahend and adding it to the minuend. 2. The 1's complement of a binary number is obtained by flipping all bits, and 1's complement subtraction involves taking the complement of the smaller number and adding it to the larger number. 3. The 2's complement is obtained by adding 1 to the 1's complement, and 2's complement subtraction discards any carry when adding the 2's complement of the smaller number to the larger number.

1. 1’s and 2’s Complements

2. Subtraction of a number from another can be accomplished by adding the complement of the subtrahend to the minuend.Introduction

3. 1’s Complement SubtractionSubtraction of binary numbers using the 1’s complement method allows subtraction only by addition.

4. The 1’s complement of a binary number can be obtained by changing all 1s to 0s and all 0s and 1s.Cont.,

5. To subtract a smaller number from a larger number, the 1’s complement method is as follows1’s complement methodDetermine the 1’s complement of the smaller number. Add this to the larger number Remove the carry and add it to the result. This carry is called end-around-carry

6. Subtract (1010)2 from (1111)2Example of 1’s complement1’s complement methodDirect Subtraction1 1 1 11’s complement0 1 0 11 1 1 11 0 1 0Carry0011 010101Add Carry1010

7. Subtraction of a large number a smaller one by the 1’s complement method involves the following stepsSubtraction StepsDetermine the 1’s complement of a large numberAdd this to the smaller numberThe answer is the 1’s complement of the result and is opposite in sign. There is no carry.

8. 2’s Complement SubtractionThe 2’s complement of a binary number can be obtained by adding 1 to its 1’s complement.

9. Subtraction of a smaller number from a larger one by the 2’s complement method involves the following stepsSteps Determine the 2’s complement of the smaller number Add this to the larger number Omit the carry ( there is always a carry in this case )

10. Example of 2’s complementSubtract (1010)2 from (1111)22’s complement methodDirect Subtraction1 1 1 11 1 1 10 1 1 02’s complement1 0 1 011 0010Carry101

11. The carry is discarded. Thus answer is (0101)2The 2’s complement method for subtraction of a large number from a smaller one is as follows.Subtraction StepsDetermine the 2’s complement of the larger numberAdd the 2’s complement to the smaller numberThere is no carry . The result is in 2’s complement form is negativeTo get an answer in true form, take the 2’s complement and change the sign.

12. Comparison between 1’s and 2’s complements

13. ….. Thank You ……The End