Square roots are another topic where mistakes can be easily made.
To try and define it in simple words lets say to ourselves, "the square root of a number is what you would multiply by itself to get the number"
For example, if I was trying to find √81
I would ask "what do I multiply by itself to get 81?" the answer is 9
So √81 = 9
Square roots of decimals:
If you were ever asked to find the square root of a decimal without a calculator, it would be a simple one that was based around the square number you should already know.
For example: Find √1.21
We need to look for a square number that has the numbers 121 in that order. We should notice that...
√121 = 11
√1.21 must be 1.1