Sometimes 32 bit is not enough. Well for those times we can use a bignum library, but why use one when you can make your own?
Big nums are numbers that go beyond the limitations of the system you are working on
For example allowing higher than 32-bit mathematics on a 32-bit processor
There are 4 main math operations that are needed to be handled
1) Addition
2) Substruction
3) Multiplication
4) Division (Some choose to ignore this, but I want to make one for fun)