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Estimate Powers and Roots

Estimate the powers and roots of the given positive numbers.

2

3

4

5

6

7

8

9

10

11

12

13

\( 2.5^2 \)

Help with roots Help with powers

Instructions

Without using a calculator estimate the value of the number in the white circle then click on the yellow circle that is the closest to your estimate.

A virtual Transum Trophy is awarded if you can achieve a score of 20. Your score will increase by one for correct answers but decrease by one for incorrect answers.

You can find more free online activities on this topic by visiting the Indices and Roots pages.

Why am I learning this?

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Go Maths

Learning and understanding Mathematics, at every level, requires learner engagement. Mathematics is not a spectator sport. Sometimes traditional teaching fails to actively involve students. One way to address the problem is through the use of interactive activities and this web site provides many of those. The Go Maths page is an alphabetical list of free activities designed for students in Secondary/High school.

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Mental Methods

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Did you know that there is a quick way of squaring a two digit number which ends in .5?

Just multiply the first digit by that digit plus one then add a 0.25 to the result.

For example What is 8.5 squared?

8 x 9 + 0.25 = 72.25.

 

You may also want to use a calculator to check your working. See Calculator Workout skill 6.

Answers to this exercise are available lower down this page when you are logged in to your Transum account. If you don’t yet have a Transum subscription one can be very quickly set up if you are a teacher, tutor or parent.

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Example

This video is from Khan Academy.

You may also want to use a calculator to check your working. See Calculator Workout skill 5.

Don't wait until you have finished the exercise before you click on the 'Check' button. Click it often as you work through the questions to see if you are answering them correctly. You can double-click the 'Check' button to make it float at the bottom of your screen.

Answers to this exercise are available lower down this page when you are logged in to your Transum account. If you don’t yet have a Transum subscription one can be very quickly set up if you are a teacher, tutor or parent.

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