In this activity, we will practise estimating square roots.

This table shows the first few whole numbers and their squares.

This means that the √81 = 9 and √100 = 10.

It also means that the square root of any number between 81 and 100 lies between 9 and 10.

We can estimate the square roots of numbers between the square numbers.

√7 is between √4 and √9  ie. 2 and 3.

So √7 is approximately 2.6  (7 is nearer to 9 than to 4)

√59 is between √49 and √64 between 7 and 8.

It is nearer to 8, so we could say it is approximately 7.7 

Let's have a go at some questions.