Question

write the rules of multiply two binary number

Answer 1

Multiplication of two binary numbers is not a difficult task. The game revolves all around two digits,i.e., 0 and 1.
For binary multiplication, keep the following rules in your mind:-

a) 0 x 0 = 0
b) 0 x 1 = 0
c) 1 x 0 = 0
d) 1 x 1 = 1  
  
For example:-
Q. Multiply 11001 with 11
Ans.
         1 1 0 0 1
            x    1 1
     ------------------
         1 1 0 0 1    =>    (  Simply multiply 11001 with 1 )
  +   1 1 0 0 1 0    =>    (  Put the zero as a placeholder as we use to do in 
   --------------------             simple decimal multiplication )
   1  0 0 1 0 1 1 
   --------------------

Q. Now how this addition happened ? 
Ans. In binary addition, there are few rules which need to be followed.

 Rules of Binary Addition are as under:
a) 0 + 0 = 0
b) 0 + 1 = 1
c) 1 + 0 = 1
d) 1 + 1= 10 ( This is a special case in which 0 is written underneath and 1 is 
                       taken as the carry )

The last 4th rule of binary addition was used above in the addition part of the above example.

Hope you got how to carry out the process of Binary Multiplication and Addition as well. Do remember the fourth rule of Binary Addition because it  is important.