Binary subtraction is also similar to that of decimal subtraction with
the difference that when 1 is subtracted from 0, it is necessary to borrow 1
from the next higher order bit and that bit is reduced by 1 (or 1 is added to
the next bit of subtrahend) and the remainder is 1.
Thus the rules of binary subtraction are as follows:
0 - 0 = 0
1 - 0 = 1
1 - 1 = 0
0 - 1 = 1 with a borrow of 1
Binary Subtraction Table
For fractional numbers, the rules of subtraction are the same with the binary point properly placed.
A clear concept on few examples will make the procedure of binary subtraction:
Subtract the following numbers:
i) 101 from 1001