# The square root of 387 must be a number between what two numbers?

Sep 16, 2016

$19 < \sqrt{387} < 20$

#### Explanation:

It helps to know the squares of the first 20 natural numbers by heart.

${20}^{2} = 400$ which is not very far from 357.

${19}^{2} = 361$

$387 \text{ is between } 361 \mathmr{and} 400$

$361 < 387 < 400$

$19 < \sqrt{387} < 20$