How to subtract 10 from 14 and 14 from 10 using 2's complement notation ?

[warlock911]

Guys need some help to solve a question. I am trying to learning Complement notation which is in my bca course. Recently i finished the 2's complement notation chapter, ans stuck at question.
Can some one describe me that how to subtract 10 from 14 , and 14 from 10 using 2's complement notation. Please use descriptive way so i can understand each step for both subtraction. Thanks in advance.

 

[awestriker]

Can these be of any help:

http://courses.cs.vt.edu/csonline/NumberSystems/Lessons/SubtractionWithTwosComplement/index.html

 

[warlock911]

Can these be of any help:

http://courses.cs.vt.edu/csonline/NumberSystems/Lessons/SubtractionWithTwosComplement/index.html

can you explain the same thing on 10 from 14?

 

[pauldmps]

Hmm, just had Digital Electronics Circuit paper this semester.

The binary subtraction would be:
1110 - 1010
= 1110 + (-1010)


Now the 2's complement of (-1010) is 0101 + 1 = 0110


Therefore : 1110 + (-1010)
= 1110 + 0110
= 10100

The resulting number must be converted to binary from its complement form.

To do that flip the digits & remove the last bit & subtract it from the remaining number:
10100 = 01011 = 0101 - 1 =0100 = 4

 

[warlock911]

Hmm, just had Digital Electronics Circuit paper this semester.

The binary subtraction would be:
1110 - 1010
= 1110 + (-1010)


Now the 2's complement of (-1010) is 0101 + 1 = 0110

Therefore : 1110 + (-1010)
= 1110 + 0110
= 10100

The resulting number must be converted to binary from its complement form.

To do that flip the digits & remove the last bit & subtract it from the remaining number:
10100 = 01011 = 0101 - 1 =0100 = 4​

Does it not require to convert 2's complement of "1110" ?

 

[pauldmps]

^^ No. You just convert the second operand i.e. the operand with a minus sign. The work of compliment is to convert a negative number to a positive one.