Multiplication and division

  • The Deca Tree
    problem

    The Deca Tree

    Age
    7 to 11
    Challenge level
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    Find out what a Deca Tree is and then work out how many leaves there will be after the woodcutter has cut off a trunk, a branch, a twig and a leaf.

  • A Square of Numbers
    problem

    A square of numbers

    Age
    7 to 11
    Challenge level
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    Can you put the numbers 1 to 8 into the circles so that the four calculations are correct?

  • Trebling
    problem

    Trebling

    Age
    7 to 11
    Challenge level
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    Can you replace the letters with numbers? Is there only one solution in each case?

  • problem

    The Brown family

    Age
    5 to 7
    Challenge level
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    Use the information about Sally and her brother to find out how many children there are in the Brown family.

  • The Pied Piper of Hamelin
    problem

    The Pied Piper of Hamelin

    Age
    7 to 11
    Challenge level
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    This problem is based on the story of the Pied Piper of Hamelin. Investigate the different numbers of people and rats there could have been if you know how many legs there are altogether!

  • Gift Stacks
    problem

    Gift stacks

    Age
    7 to 11
    Challenge level
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    Use the information to work out how many gifts there are in each pile.
  • Clever Santa
    problem

    Clever Santa

    Age
    7 to 11
    Challenge level
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    All the girls would like a puzzle each for Christmas and all the boys would like a book each. Solve the riddle to find out how many puzzles and books Santa left.

  • Clock Face
    problem

    Clock face

    Age
    7 to 11
    Challenge level
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    Where can you draw a line on a clock face so that the numbers on both sides have the same total?

  • A One in Seven Chance
    problem

    A one in seven chance

    Age
    11 to 14
    Challenge level
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    What is the remainder when 2^{164}is divided by 7?
  • A Conversation Piece
    problem

    A conversation piece

    Age
    7 to 11
    Challenge level
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    Take the number 6 469 693 230 and divide it by the first ten prime numbers and you'll find the most beautiful, most magic of all numbers. What is it?