Here is another quick trick.
As you probably know, the square of a number is a number multiplied by itself. For example, the square of 7 is 7 x 7 = 49.

Later, I will teach you a simple method that will enable you to easily calculate the square of any two-digit or three-digit (or higher) number. That method is especially simple when the number ends in 5,

so let’s do that trick now.
To square a two-digit number that ends in 5, you need to remember only two things.


1. The answer begins by multiplying the first digit by the next higher digit.
2. The answer ends in 25.


                 35
               x35
3 x 4 = 12
5 x 5 =     25
Answer:1225