Working systematically

  • problem
    Favourite

    Two Primes Make One Square

    Age
    7 to 11
    Challenge level
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    Can you make square numbers by adding two prime numbers together?

  • problem
    Favourite

    Orange Drink

    Age
    7 to 11
    Challenge level
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    A 750 ml bottle of concentrated orange squash is enough to make fifteen 250 ml glasses of diluted orange drink. How much water is needed to make 10 litres of this drink?

  • Andy's Marbles
    problem
    Favourite

    Andy's Marbles

    Age
    7 to 11
    Challenge level
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    Andy had a big bag of marbles but unfortunately the bottom of it split and all the marbles spilled out. Use the information to find out how many there were in the bag originally.

  • Finding Fifteen
    problem
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    Finding Fifteen

    Age
    7 to 11
    Challenge level
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    Tim had nine cards each with a different number from 1 to 9 on it. How could he have put them into three piles so that the total in each pile was 15?

  • More Transformations on a Pegboard
    problem
    Favourite

    More Transformations on a Pegboard

    Age
    7 to 11
    Challenge level
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    Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.

  • problem
    Favourite

    Factor-Multiple Chains

    Age
    7 to 11
    Challenge level
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    Can you see how these factor-multiple chains work? Find the chain which contains the smallest possible numbers. How about the largest possible numbers?

  • Route Product
    problem
    Favourite

    Route Product

    Age
    7 to 11
    Challenge level
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    Find the product of the numbers on the routes from A to B. Which route has the smallest product? Which the largest?

  • problem
    Favourite

    Oh! Harry!

    Age
    7 to 11
    Challenge level
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    A group of children are using measuring cylinders but they lose the labels. Can you help relabel them?

  • Light the Lights Again
    problem
    Favourite

    Light the Lights Again

    Age
    7 to 11
    Challenge level
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    Each light in this interactivity turns on according to a rule. What happens when you enter different numbers? Can you work out the rule for each light?

  • problem
    Favourite

    This Pied Piper of Hamelin

    Age
    7 to 11
    Challenge level
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    Investigate the different numbers of people and rats there could have been if you know how many legs there are altogether!