Calculate square of a three digit number

In competitive exams where every second is precious, it becomes necessary to save time and use tricks to solve problems. Tricks helps to save crucial time and solve the problem with greater accuracy. So I am going to show you how to find square of a given three digit number.


Suppose you want to find square of abc

Step 1
Units digit = units digit of  sqr(c), and carry over the tenth digit.

Step 2
tens digit = units digit of 2*b*c + carry from previous step.

Step 3
Hundreds digit= units digit of 2*a*c + sqr(b) + carry from previous step.

Step 4
Thousands digit = 2*a*b + carry from previous step.

Step 5
Final digit = sqr(a) + carry from previous step.