Calculate Square Roots (Without a Calculator)

Square roots are a 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 reach this number."

e.g. If we are trying to find √81...

We should ask ourselves first:

"What do I multiply by itself to reach 81?"

The answer is 9.

So √81 = 9

Square roots of decimals

If you are ever asked to find the square root of a decimal without a calculator, it is much simpler to use a square number that you already know.

e.g. 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

Therefore, √1.21 must be 1.1

Simple!

In this activity, you will find square roots of whole numbers and decimals without using a calculator. 

When finding the square root of a decimal, you will need to relate it to a whole square number.