Transum Software

Mental Strategies

Practise your mental arithmetic skills and learn some new strategies with this self marking exercise.

Level 1 Level 2 Level 3 Level 4 Description Help More...
No calculator

This is level 1: mental strategies for addition. Click on the blue question mark buttons for strategy suggestions.

13 + 14
?

Correct Wrong

11 + 21 + 89
?

Correct Wrong

57 + 59
?

Correct Wrong

64 + 69
?

Correct Wrong

71 + 53
?

Correct Wrong

73 + 74
?

Correct Wrong

90 + 91
?

Correct Wrong

116 + 109
?

Correct Wrong

122 + 123
?

Correct Wrong

100 + 129
?

Correct Wrong

141 + 119
?

Correct Wrong

126 + 149
?

Correct Wrong

134 + 172
?

Correct Wrong

164 + 175
?

Correct Wrong

188 + 149
?

Correct Wrong

203 + 181
?

Correct Wrong

210 + 180
?

Correct Wrong

220 + 180
?

Correct Wrong

Check

This is Mental Strategies level 1. You can also try:
Level 2 Level 3 Level 4

Instructions

Try your best to answer the questions above. Type your answers into the boxes provided leaving no spaces. As you work through the exercise regularly click the "check" button. If you have any wrong answers, do your best to do corrections but if there is anything you don't understand, please ask your teacher for help.

When you have got all of the questions correct you may want to print out this page and paste it into your exercise book. If you keep your work in an ePortfolio you could take a screen shot of your answers and paste that into your Maths file.

Why am I learning this?

Mathematicians are not the people who find Maths easy; they are the people who enjoy how mystifying, puzzling and hard it is. Are you a mathematician?

Comment recorded on the 23 September 'Starter of the Day' page by Judy, Chatsmore CHS:

"This triangle starter is excellent. I have used it with all of my ks3 and ks4 classes and they are all totally focused when counting the triangles."

Comment recorded on the 5 April 'Starter of the Day' page by Mr Stoner, St George's College of Technology:

"This resource has made a great deal of difference to the standard of starters for all of our lessons. Thank you for being so creative and imaginative."

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Featured Activity

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A fascinating digit changing challenge. Change the numbers on the apples so that the number on the lemon is the given total. Can you figure out, by understanding place value, how this works?

Answers

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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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Are you looking for something specific? An exercise to supplement the topic you are studying at school at the moment perhaps. Navigate using our Maths Map to find exercises, puzzles and Maths lesson starters grouped by topic.

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If you found this activity useful don't forget to record it in your scheme of work or learning management system. The short URL, ready to be copied and pasted, is as follows:

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Scan the QR code below to visit the online version of this activity.

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Description of Levels

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Level 1 - Mental strategies for addition

Level 2 - Mental strategies for subtraction

Level 3 - Mental strategies for multiplication

Level 4 - Mental strategies for division

More Mental Methods including lesson Starters, visual aids, investigations and self-marking exercises.

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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Curriculum Reference

See the National Curriculum page for links to related online activities and resources.

Extension Activity

Make up a ten-question mental arithmetic exercise for a friend. For each question you should secretly write down your prediction of which strategy they will use. You should include addition, subtraction, multiplication and division questions and your ten predictions should all be different.

Strategies to Add Mentally

Adjusting

35 + 9
= 35 + 10 − 1
= 45 − 1
= 44

Equivalent calculations

34 + 35
= 2 × 34 + 1
= 68 + 1
= 69

Partition both numbers

21 + 45
= 20 + 1 + 40 + 5
= 20 + 40 + 1 + 5
= 60 + 6
= 66

Partition second number

53 + 36
= 53 + 30 + 6
= 83 + 6
= 89

Common zeros

120 + 70
(12 + 7 = 19)
= 190

Reordering

8 + 7 + 2
= 8 + 2 + 7
= 10 + 7
= 17

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.

Log in Sign up

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