How to Find Square Root of any number in 5 seconds

The square root of any number can be found by this simple trick.

First of all, we should know the squares of all the numbers from 1 to 9.

1x1 = 1

2x2 = 4

3x3 = 9

4x4 = 16

5x5 = 25

6x6 = 36

7x7 = 49

8x8 = 64

9x9 = 81

Now we have memorize the last digit of squares of every number,

For ease, the last digit is same 

1 for 1,9

4 for 2,8

9 for 3,7

6 for 4,6

5 for 5

Now lets us take an example for learning the steps.

Q. What is the square root of 6084?

Step1.

Notice the last digit of number 

here it is 4, which means our last digit of answer could be 2 or 8,

Step2.

Now ignore the last pair of digits in question i.e. 84

The remaining digits are 60

Now check that, 60 fall in between squares of which two numbers

here 60 fall in between 49 and 64 which are the squares of 7 and 8.

we have to take the lower number so, the first digit of answer is 7

Step3.

Now multiply these two numbers, 7x8 = 56

56 is lower than 60 so the last digit of answer is the higher number in pair we found in step 1 i.e. 8

So, the answer of question is 78.

If the multiplication is higher than remaining pair, we have to take the lower number we found in step 1.

Q2. what is the square root of 8281?

Step1.

The last digit is 1 so the last digit of answer could be 1 or 9

Step2. 

ignoring the last pair of digits

now we remain with 82

82 fall in between the squares of 9 and 10

9 is the lower number so the first digit of answer is 9.

Step3.

Multiplication of 9x10 = 90

as 90 is higher than 82 

so last digit of answer is lower number we found in the step 1 i.e. 1

So the answer is  91.

Now try it yourself.