Explaining, convincing and proving

  • circles in quadrilaterals
    problem
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    Circles in Quadrilaterals

    Age
    14 to 16
    Challenge level
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    Explore when it is possible to construct a circle which just touches all four sides of a quadrilateral.

  • A little light thinking
    problem
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    A Little Light Thinking

    Age
    14 to 16
    Challenge level
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    Here is a machine with four coloured lights. Can you make two lights switch on at once? Three lights? All four lights?

  • Last one standing
    problem
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    Last One Standing

    Age
    14 to 16
    Challenge level
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    Imagine a room full of people who keep flipping coins until they get a tail. Will anyone get six heads in a row?

  • Finding factors
    problem
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    Finding Factors

    Age
    14 to 16
    Challenge level
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    Can you find the hidden factors which multiply together to produce each quadratic expression?

  • Generating Triples
    problem
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    Generating Triples

    Age
    14 to 16
    Challenge level
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    Sets of integers like 3, 4, 5 are called Pythagorean Triples, because they could be the lengths of the sides of a right-angled triangle. Can you find any more?

  • problem
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    Who's the Winner?

    Age
    14 to 16
    Challenge level
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    When two closely matched teams play each other, what is the most likely result?

  • Double Trouble
    problem
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    Double Trouble

    Age
    14 to 16
    Challenge level
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    Simple additions can lead to intriguing results...

  • Factorising with Multilink
    problem
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    Factorising With Multilink

    Age
    14 to 16
    Challenge level
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    Can you find out what is special about the dimensions of rectangles you can make with squares, sticks and units?

  • Nutrition and Cycling
    problem
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    Nutrition and Cycling

    Age
    14 to 16
    Challenge level
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    Andy wants to cycle from Land's End to John o'Groats. Will he be able to eat enough to keep him going?