Working systematically

  • Football Sum
    problem

    Football Sum

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

    Find the values of the nine letters in the sum: FOOT + BALL = GAME

  • Pair Sums
    problem

    Pair Sums

    Age
    11 to 14
    Challenge level
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    Five numbers added together in pairs produce: 0, 2, 4, 4, 6, 8, 9, 11, 13, 15 What are the five numbers?

  • Coins
    problem

    Coins

    Age
    11 to 14
    Challenge level
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    A man has 5 coins in his pocket. Given the clues, can you work out what the coins are?

  • Distinct in a Line
    problem

    Distinct in a Line

    Age
    11 to 14
    Challenge level
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    This grid can be filled so that each of the numbers 1, 2, 3, 4, 5 appears just once in each row, column and diagonal. Which number goes in the centre square?

  • Almost Constant Digits
    problem

    Almost Constant Digits

    Age
    11 to 14
    Challenge level
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    How many 10-digit numbers containing only 1s, 2s and 3s can you write?

  • Kangaroo Hops
    problem

    Kangaroo Hops

    Age
    11 to 14
    Challenge level
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    Weekly Problem 11 - 2011
    Kanga hops ten times in one of four directions. At how many different points can he end up?

  • The Best Card Trick?
    problem

    The Best Card Trick?

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

    Time for a little mathemagic! Choose any five cards from a pack and show four of them to your partner. How can they work out the fifth?

  • Wallpaper Sudoku
    problem

    Wallpaper Sudoku

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

    A Sudoku that uses transformations as supporting clues.

  • Seasonal Twin Sudokus
    problem

    Seasonal Twin Sudokus

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

    This pair of linked Sudokus matches letters with numbers and hides a seasonal greeting. Can you find it?

  • Ratio Sudoku 2
    problem

    Ratio Sudoku 2

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

    A Sudoku with clues as ratios.