Question

What is the square root of 7921?

Answer 1

89

Explanation:

What's the bigger perfect square minor than 7921?
is 64.
The square root will start by a 8 (`sqrt(64)`)

1) Subract 6400 from 7921 and you obtain 1521.

2)take 8 multiply it by 20 and add find the larger number

`bar(16n)xxn` smaller or equal than 1521. `169xx9` is exactly 9

3) so the solution is 89