Mental calculations

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Mind Reading

Age

11 to 14

Challenge level

1 out of 3

Think of a number, add one, double it, take away 3, add the number you first thought of, add 7, divide by 3 and take away the number you first thought of. You should now be left with 2. How do I know?
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Two Dice

Age

5 to 7

Challenge level

1 out of 3

Find all the numbers that can be made by adding the dots on two dice.
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One Big Triangle

Age

5 to 7

Challenge level

1 out of 3

Make one big triangle so the numbers that touch on the small triangles add to 10.
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Butterfly Flowers

Age

5 to 7

Challenge level

1 out of 3

Can you find two butterflies to go on each flower so that the numbers on each pair of butterflies adds to the number on their flower?
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What's in a Name?

Age

5 to 7

Challenge level

1 out of 3

What do you notice about these squares of numbers? What is the same? What is different?
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Number Balance

Age

5 to 7

Challenge level

1 out of 3

Can you hang weights in the right place to make the the number balance balanced?
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Domino Sorting

Age

5 to 7

Challenge level

1 out of 3

Try grouping the dominoes in the ways described. Are there any left over each time? Can you explain why?
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Number Lines

Age

5 to 7

Challenge level

1 out of 3

Leah and Tom each have a number line. Can you work out where their counters will land?
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Sort Them Out (1)

Age

5 to 7

Challenge level

1 out of 3

Can you each work out the number on your card? What do you notice? How could you sort the cards?
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Pairs of Numbers

Age

5 to 7

Challenge level

1 out of 3

If you have ten counters numbered 1 to 10, how many can you put into pairs that add to 10? Which ones do you have to leave out? Why?