Question

Find the square root of 841 without prime factorisation.

Answer 1

841 lies between 400 and 900

So the square root of 841 lies between 20 and 30

Since the last digit of 841 is 1, its last digit of its square root will be 1 or 9.

So the square root can be 21 or 29. But since 841 is closer to 900, the square root of 841 is 29.