One of the reasons that computers use binary numbers is that it is easier for computers to perform basic arithmetic, such as addition and multiplication.
Computers use basic Boolean algebra (a form of logic) to handle addition and repeated addition and bit-shifting to perform multiplication.
Binary addition is really simple:
0 + 0 = 0 0 + 1 = 1 + 0 = 1 1 + 1 = 10, which means that there is a carry.
Example
11 <-- These are the carries 0101 1001 0010 0011 ========= 0111 1100
Multiplying means adding repeatedly and shifting when we add:
0011 0011 ======== 0011 0011 0000 0000 ======== 00001001
Using this method, add the following values:
a. 1100 0001 b. 0011 1010
1001 0010 1101 0101
========= =========
Multiply the following values:
c. 1010 d. 0010
0101 0110
==== ====