Conjecturing and generalising

  • Last one standing
    problem
    Favourite

    Last One Standing

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

    Imagine a room full of people who keep flipping coins until they get a tail. Will anyone get six heads in a row?

  • Which is cheaper?
    problem
    Favourite

    Which Is Cheaper?

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

    When I park my car in Mathstown, there are two car parks to choose from. Can you help me to decide which one to use?

  • Generating Triples
    problem
    Favourite

    Generating Triples

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

    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?

  • Beelines
    problem
    Favourite

    Beelines

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

    Is there a relationship between the coordinates of the endpoints of a line and the number of grid squares it crosses?

  • Hollow Squares
    problem
    Favourite

    Hollow Squares

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

    Which armies can be arranged in hollow square fighting formations?

  • Two Ladders
    problem
    Favourite

    Two Ladders

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

    Two ladders are propped up against facing walls. At what height do the ladders cross?

  • Odd Differences
    problem
    Favourite

    Odd Differences

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

    The diagram illustrates the formula: 1 + 3 + 5 + ... + (2n - 1) = n² Use the diagram to show that any odd number is the difference of two squares.

  • Expenses
    problem
    Favourite

    Expenses

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

    What is the largest number which, when divided into these five numbers in turn, leaves the same remainder each time?

  • Plus Minus
    problem
    Favourite

    Plus Minus

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

    Can you explain the surprising results Jo found when she calculated the difference between square numbers?

  • Of all the areas
    problem
    Favourite

    Of All the Areas

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

    Can you find a general rule for finding the areas of equilateral triangles drawn on an isometric grid?