Question

Find the largest number of 3 digits which is a perfect square.

Answer 1

At first, 

The largest 3 digit number = 999 

Now, 

The number whose square is 999 is 31.61 (approx.) 

Hence, 

The square of any number greater than 31.61 would be a 4-digit number. 

Therefore, 

The square of 31 will be the greatest 3 digit perfect square. 

We can calculate the largest 3 digit perfect square number as: 

31² = 31 × 31 

= 961