XX x XX (the total number of first number is 10, same both digit of second number)

Formulas :

First 2 digits = [ __ x ( __ + 1 )]

Last 2 digits = __ x __

Example :

37 x 44

First 2 digits = [4 × ( 3 + 1 )]

= 16

Last 2 digits = 7 × 4

= 28

So, 37 × 44 = 1628