Imagine you need to implement (integer) mulitplication in code. Maybe you are on a system which doesn't have it or something. How to do this, and what is the minimal set of operators that are required?
The most obvious way to do multiplition is through repeated addition. To get the answer to 56 x 67 you add 56 to itself 67 times (or 67, 56 times - the order doesn't matter).
This is simple to implement if we assume for the moment that both a and b are positive (we will deal with negative integers later)
