- Binary subtraction
As in the case of binary addition, in binary subtraction also the following rules are to
be followed.
0 – 0 = 0
1 – 0 = 1
1 – 1 = 0
10 – 1 = 1
11 – 1 = 10
100 – 1 = 11
101 - 1 = 100
110 – 1 = 101
111 – 1 = 110Eg. : Subtract 1111 – 1011- Binary multiplication
As the binary system involves only two digits 0 and 1, the entire multiplication
process is complete with the knowledge of the product of these two digits in different
combinations. Once the digits are multiplied the rest is only addition of the two or
more digits involving 0 and 1.
The basic rules regarding multiplication in binary system are,
(^0) × 0 = 0
(^0) × 1 = 0
(^1) × 0 = 0
(^1) × 1 = 1
The same logic applies in subtraction too. For
example, 10 – 1 = 9 but the next lowest binary
number is 1 and therefore, 10 –1 = 1. However,
11 – 1 = 10 which is already in the form of a
binary number. Similarly 1000 – 1 = 111. since
111 is the next available number with binary
coding. The child should not confuse the binary
addition and subtraction with the regular addition
or subtraction.