For example, √4, the answers are +2 and -2. √36, the answers are +6 and -6.

The answer is that there are two numbers, but positive numbers are usually used in practical problems, but it also depends on the situation.

Not all the results from the roots of numbers are integers, such as √8. When you can't find the integer answer, you can try to disassemble this number, that is, √ 8 = √ 4 * √ 2 = √ 4 can be the root (√4=2), so it becomes 2*√2.

This should be understood as simplification, a bit like the reduction of scores. This is my personal understanding. You don't have to understand it that way.

There are many similar ones, such as √20=√4*5=√4*√5=2*√5=2√5.

Numbers within 100 can be simplified by written examination. If it is like √72, then the larger number √36 should be given priority, that is √ 72 = √ 36 * 2 = √ 36 * √ 2 = 6 * √ 2, so that it can be achieved in one step. Instead of considering the decimal √4 first, it will become more troublesome.

That's all I can think of for the time being. If you have any other questions, you can ask them and try to answer them.