Square a 2 Digit Number Ending in 5

Square a 2 Digit Number Ending in 5

For this example we will use 25

* Take the "tens" part of the number (the 2 and add 1)=3
* Multiply the original "tens" part of the number by the new number (2x3)
* Take the result (2x3=6) and put 25 behind it. Result the answer 625.

Try a few more 75 squared ... = 7x8=56 ... put 25 behind it is 5625.
55 squared = 5x6=30 ... put 25 behind it ... is 3025.