Some Useful Tricks to do Math Fast

Quick Square of two digit number end in 5

There are two rules.

(1)Multiply the Tens place digit by itself plus 1.

(2) square the First place digit and put a 25 at the end.

 45 squared 

 ten place digit 4=4*(4+1)= 4*5=20

First place digit 5=(5)²=25

^{Then the Answer = 2025}