How do you do this

Question

asked Mar 19, 2021 129k views

2 Answers

Vadim Belman · Answer 1 · 2021-03-22T00:14:40+0000

Answer:

The best choice is to use a calculator (the button is
$\sqrt$ ), but if that is not an option here are a few tips.

If a perfect square ends with a 1, then the last digit of its square root has to be either 1 or 9.

If a perfect square ends with a 4, then the last digit of its square root has to be either 2 or 8.

If a perfect square ends with a 5, then the last digit of its square root is definitely 5.

If a perfect square ends with a 6, then the last digit of its square root has to be either 4 or 6.

If a perfect square ends with a 9, then the last digit of its square root has to be either 3 or 7.

I took a look and all of them seem to be perfect squares so hopefully this helps!