Determination of the concentration of hands.

I will try here, how to calculate the square root of any integer integers, that is to say the beginning of the rule and then from there to find out the rules of the solid. Then the interested ones can find the n-root, and some instructions will be given.
Rules of class and behind it:
The actual thing is the same thing (10a + b) ² = 100a² + 20ab + b²
Any positive integer number with multiple digits can be written as (10a + b). For example 23 can be written 10 × 2 + 3 Again 113 can be written 10 × 11 + 3 Keeping this in mind, we pay attention to the square root rules.
Suppose we want to find out the square root of 169.