Reasoning, convincing and proving

  • Road maker
    problem

    Road maker

    Age
    14 to 18
    Challenge level
    filled star empty star empty star
    Which of these roads will satisfy a Munchkin builder?
  • Impossible square?
    problem

    Impossible square?

    Age
    16 to 18
    Challenge level
    filled star filled star empty star
    Can you make a square from these triangles?
  • Consecutive negative numbers
    problem

    Consecutive negative numbers

    Age
    11 to 14
    Challenge level
    filled star filled star filled star

    Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?

  • t for Tan
    problem

    T for tan

    Age
    16 to 18
    Challenge level
    filled star empty star empty star

    Can you find a way to prove the trig identities using a diagram?

  • 9 Weights
    problem

    9 weights

    Age
    11 to 14
    Challenge level
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    You have been given nine weights, one of which is slightly heavier than the rest. Can you work out which weight is heavier in just two weighings of the balance?
  • Overlaps
    problem

    Overlaps

    Age
    7 to 11
    Challenge level
    filled star filled star empty star

    What does the overlap of these two shapes look like? Try picturing it in your head and then use some cut-out shapes to test your prediction.

  • The Great Weights Puzzle
    problem

    The great weights puzzle

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    You have twelve weights, one of which is different from the rest. Using just 3 weighings, can you identify which weight is the odd one out, and whether it is heavier or lighter than the rest?
  • Gutter
    problem

    Gutter

    Age
    14 to 16
    Challenge level
    filled star filled star empty star

    Manufacturers need to minimise the amount of material used to make their product. What is the best cross-section for a gutter?

  • Honey Bees
    problem

    Honey bees

    Age
    14 to 16
    Challenge level
    filled star empty star empty star
    How many bees could fly 1000 miles if they had 10 gallons of honey?