Square any two digits number that ends with 5 [Math Tips & Tricks]

Calculating the square of a number below 100 is extremely simple. If you want to find the square of 35 for example, you simply have to take the first digit (3), multiply it for the next higher number (4), and then add 25 to the result.

Example:

35^2 = (3x4)25 = 1225

Amazon Item for Mathslovers

How Not to be Wrong: The Hidden Maths of Everyday Life