We have two methods to do this
One is that we can start writing the squares of numbers and once we reach a number whose square is greater than 500 , we stop on one number less,
But this may take time ,
instead
What we can do is that
We know that 2^2 = 4
So simply 20^2 = 400
and 25^2 = 625
Now it means our answer lies somewhere in between 20 and 25 , Let's check the square of 23
23^2 = 529
and 22^2 = 484
So that's it
we get our answer
1 to 22
It means 22 counting numbers have less than 500 as there squares