Explaining, convincing and proving

  • problem
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    Three Neighbours

    Age
    7 to 14
    Challenge level
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    Take three consecutive numbers and add them together. What do you notice?

  • problem
    Favourite

    Inky Cube

    Age
    7 to 14
    Challenge level
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    This cube has ink on each face which leaves marks on paper as it is rolled. Can you work out what is on each face and the route it has taken?

  • A cardboard carton of cherries.
    problem
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    Fruity Totals

    Age
    7 to 16
    Challenge level
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    In this interactivity each fruit has a hidden value. Can you deduce what each one is worth?

  • 5 by 5 Mathdokus
    problem
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    5 by 5 Mathdokus

    Age
    7 to 16
    Challenge level
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    Can you use the clues to complete these 5 by 5 Mathematical Sudokus?

  • Xavi's T-shirt
    problem
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    Xavi's T-Shirt

    Age
    7 to 16
    Challenge level
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    How much can you read into a T-shirt?

  • Angles inside
    problem
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    Angles Inside

    Age
    11 to 14
    Challenge level
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    Draw some angles inside a rectangle. What do you notice? Can you prove it?

  • An American flag waving in the wind.
    problem
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    American Billions

    Age
    11 to 14
    Challenge level
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    Play the divisibility game to create numbers in which the first two digits make a number divisible by 2, the first three digits make a number divisible by 3...

  • Blue and White
    problem
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    Blue and White

    Age
    11 to 14
    Challenge level
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    Identical squares of side one unit contain some circles shaded blue. In which of the four examples is the shaded area greatest?

  • Special Numbers
    problem
    Favourite

    Special Numbers

    Age
    11 to 14
    Challenge level
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    My two digit number is special because adding the sum of its digits to the product of its digits gives me my original number. What could my number be?

  • Tilted Squares
    problem
    Favourite

    Tilted Squares

    Age
    11 to 14
    Challenge level
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    It's easy to work out the areas of most squares that we meet, but what if they were tilted?