Reasoning, convincing and proving

  • problem

    Doughnut percents

    Age
    7 to 14
    Challenge level
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    Can you work as a team to make doughnuts by matching these fractions, decimals and percentages?

  • Number match
    problem

    Number match

    Age
    5 to 7
    Challenge level
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    Can you work as a group to match these numbers?

  • Partly Painted Cube
    problem

    Partly painted cube

    Age
    14 to 16
    Challenge level
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    Jo made a cube from some smaller cubes, painted some of the faces of the large cube, and then took it apart again. 45 small cubes had no paint on them at all. How many small cubes did Jo use?

  • How do you do it?
    problem

    How do you do it?

    Age
    7 to 11
    Challenge level
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    This group activity will encourage you to share calculation strategies and to think about which strategy might be the most efficient.

  • Close to triangular
    problem

    Close to triangular

    Age
    14 to 16
    Challenge level
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    Drawing a triangle is not always as easy as you might think!
  • Matrix meaning
    problem

    Matrix meaning

    Age
    16 to 18
    Challenge level
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    Explore the meaning behind the algebra and geometry of matrices with these 10 individual problems.

  • Mixing Lemonade
    problem

    Mixing lemonade

    Age
    11 to 14
    Challenge level
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    Can you work out which drink has the stronger flavour?

  • Times Tables Shifts
    problem

    Times tables shifts

    Age
    7 to 11
    Challenge level
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    In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?

  • Knights and Knaves
    problem

    Knights and knaves

    Age
    11 to 14
    Challenge level
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    Knights always tell the truth. Knaves always lie. Can you catch these knights and knaves out?
  • Distinct Diagonals
    problem

    Distinct diagonals

    Age
    11 to 14
    Challenge level
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    Weekly Problem 21 - 2010
    How many diagonals can you draw on this square...