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

warlock911

Member
Disciple
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.

pauldmps

Well-Known Member
Veteran
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

warlock911

Member
Disciple
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

Well-Known Member
Veteran
^^ 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.

• warlock911 and dark.lord.rules