Question

Multiply 7x13 in binary.

Answer 1

7 = 00110111

13 = 00110001 00110011

7 x 13 = 91

00110111 x 00110001 00110011 = 00111001 00110001

Answer 2

1011011

Explanation:

The binary multiplication is pretty much like the decimal one, we have just to remember that in the binary system 1+1 = 10.

First, convert 7 and 13 to binary

7 = 111

13 = 1101

now multiply with the same rules as in decimal

1101x

111

--------------

1101+

1101 +

1101

1111

-------------

1011011

The last row of digits are the carry bits.

So 7*13 = 1101*111(binary) = 1011011 (binary)