XX² (any number between 2-99)

Formulas :

100 − __ = __  

First 2 digits = 100 − ( __ + __ )

Last 2 digits = __²

Example :

98²

100 − 98 = 2

First 2 digits = 100 − ( 2 + 2 )

= 100 − 4

= 96

Last 2 digits = 2²

= 4

So, 98² = 9604