Explaining, convincing and proving

  • Fibonacci Surprises
    problem
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    Fibonacci Surprises

    Age
    11 to 14
    Challenge level
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    Play around with the Fibonacci sequence and discover some surprising results!

  • The Farmers' Field Boundary
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    The Farmers' Field Boundary

    Age
    11 to 14
    Challenge level
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    The farmers want to redraw their field boundary but keep the area the same. Can you advise them?

  • What numbers can we make now?
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    What Numbers Can We Make Now?

    Age
    11 to 14
    Challenge level
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    Imagine we have four bags containing numbers from a sequence. What numbers can we make now?

  • Four playing cards on top of each other. Each card shows a different ace.
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    Snappy Statements

    Age
    11 to 14
    Challenge level
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    Use properties of numbers to work out whether you can satisfy all these statements at the same time.

  • Differences
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    Differences

    Age
    11 to 14
    Challenge level
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    Can you guarantee that, for any three numbers you choose, the product of their differences will always be an even number?

  • Cuboids
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    Cuboids

    Age
    11 to 14
    Challenge level
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    Can you find a cuboid that has a surface area of exactly 100 square units. Is there more than one? Can you find them all?

  • Litov's Mean Value Theorem
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    Litov's Mean Value Theorem

    Age
    11 to 14
    Challenge level
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    Start with two numbers and generate a sequence where the next number is the mean of the last two numbers...

  • Consecutive negative numbers
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    Consecutive Negative Numbers

    Age
    11 to 14
    Challenge level
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    Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?

  • the greedy algorithm
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    The Greedy Algorithm

    Age
    11 to 14
    Challenge level
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    The Egyptians expressed all fractions as the sum of different unit fractions. The Greedy Algorithm might provide us with an efficient way of doing this.

  • Which solids can we make?
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    Which Solids Can We Make?

    Age
    11 to 14
    Challenge level
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    Interior angles can help us to work out which polygons will tessellate. Can we use similar ideas to predict which polygons combine to create semi-regular solids?