How many ways to answer 99 multiplication 99?

Answer 1

It is 9801 and is one of the things I have remembered form over the years (sad, isn't it!).

The simplest way to calculate it is:

99*99 = 992 = (100 - 1)2 = 1002 - 2*100*1 + 12 = 10000 - 200 + 1 = 9801