Exploring and noticing

  • Which list is which?
    problem
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    Which list is which?

    Age
    14 to 16
    Challenge level
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    Six samples were taken from two distributions but they got muddled up. Can you work out which list is which?

  • Difference of Two Squares
    problem
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    Difference of two squares

    Age
    14 to 16
    Challenge level
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    What is special about the difference between squares of numbers adjacent to multiples of three?

  • Square Number Surprises
    problem
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    Square number surprises

    Age
    14 to 16
    Challenge level
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    There are unexpected discoveries to be made about square numbers...

  • Ladder and Cube
    problem
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    Ladder and cube

    Age
    14 to 16
    Challenge level
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    A 1 metre cube has one face on the ground and one face against a wall. A 4 metre ladder leans against the wall and just touches the cube. How high is the top of the ladder above the ground?

  • Bendy Quad
    problem
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    Bendy quad

    Age
    14 to 16
    Challenge level
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    Four rods are hinged at their ends to form a convex quadrilateral. Investigate the different shapes that the quadrilateral can take. Be patient this problem may be slow to load.

  • Tet-Trouble
    problem
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    Tet-trouble

    Age
    14 to 16
    Challenge level
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    Is it possible to have a tetrahedron whose six edges have lengths 10, 20, 30, 40, 50 and 60 units?

  • Napkin
    problem
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    Napkin

    Age
    14 to 16
    Challenge level
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    A napkin is folded so that a corner coincides with the midpoint of an opposite edge. Investigate the three triangles formed.

  • Hexy-Metry
    problem
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    Hexy-metry

    Age
    14 to 16
    Challenge level
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    A hexagon, with sides alternately a and b units in length, is inscribed in a circle. How big is the radius of the circle?

  • Squirty
    problem
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    Squirty

    Age
    14 to 16
    Challenge level
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    Using a ruler, pencil and compasses only, it is possible to construct a square inside any triangle so that all four vertices touch the sides of the triangle.

  • Dating made Easier
    problem
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    Dating made easier

    Age
    14 to 16
    Challenge level
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    If a sum invested gains 10% each year how long before it has doubled its value?