Find the square root of 324

Given number is $324 .$

Now, we subtract successive odd numbers starting from 1 as follows:

Here, $\quad 324-1=323, \quad 323-3=320$

$320-5=315, \quad 315-7=308$

$308-9=299, \quad 299-11=288$

$288-13=275,275-15=260$

$260-17=243,243-19=224$

$224-21=203,203-23=180$

$180-25=155,155-27=128$

$128-29=99, \quad 99-31=68$

$68-33=35, \quad 35-35=0$

We observe that the number 324 reduced to zero $(0)$ after subracting 18 odd numbers. So, 324 is a perfect square of 18 .

$\therefore \sqrt{324}=18$

Hence, the square root of 324 is $18 .$