Question

Find the least number that must be subtracted from the following number so as to get a perfect square. Also find the square root of the perfect square so obtained.

402

Answer 1

The square root of 402 can be calculated by the long division method as follows:

	20
2	`bar4  bar02` -4
40	02  -00
	2

The remainder is 2. It represents that the square of 20 is less than 402 by 2. Therefore, a perfect square will be obtained by subtracting 2 from the given number 402.

Therefore, required perfect square = 402 − 2 = 400

And `sqrt400` = 20