what is the biggest number possible?

why dont you have a look at this, maybe this can help!

http://en.wikipedia.org/wiki/Largest_number

and if u still dont understand then pls be free to ask!

hope this helps!

There is no biggest number. For example, if you have a really long number, you can always add 1. So because of this, there is no biggest number. That's why somebody made up the word infinity because in numbers, there is no ending. 

Definition of Infinity: A "number" which has no end and no beggining.

Hope it helps!