Mental calculations

  • Going round in circles
    problem
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    Going Round in Circles

    Age
    11 to 14
    Challenge level
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    Mathematicians are always looking for efficient methods for solving problems. How efficient can you be?

  • Mixing Lemonade
    problem
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    Mixing Lemonade

    Age
    11 to 14
    Challenge level
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    Can you work out which drink has the stronger flavour?

  • Can you Make 100?
    problem
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    Can You Make 100?

    Age
    11 to 14
    Challenge level
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    How many ways can you find to put in operation signs (+, −, ×, ÷) to make 100?

  • Where can we visit?
    problem
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    Where Can We Visit?

    Age
    11 to 14
    Challenge level
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    Charlie and Abi put a counter on 42. They wondered if they could visit all the other numbers on their 1-100 board, moving the counter using just these two operations: ×2 and -5. What do you think?

  • Thousands and Millions
    problem
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    Thousands and Millions

    Age
    11 to 14
    Challenge level
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    Here's a chance to work with large numbers...

  • Overlaps
    problem
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    Overlaps

    Age
    11 to 14
    Challenge level
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    Can you find ways to put numbers in the overlaps so the rings have equal totals?

  • Power Countdown
    problem
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    Power Countdown

    Age
    14 to 16
    Challenge level
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    In this twist on the well-known Countdown numbers game, use your knowledge of Powers and Roots to make a target.

  • Difference Sudoku
    problem
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    Difference Sudoku

    Age
    14 to 16
    Challenge level
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    Use the differences to find the solution to this Sudoku.

  • content-03-01-cupboardlove2-sol1.gif
    problem

    Transformations Tables

    Age
    7 to 11
    Challenge level
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    These grids are filled according to some rules - can you complete them?
  • Street Lamps
    problem

    Street Lamps

    Age
    11 to 14
    Challenge level
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    Walking up a steep hill, I pass 10 equally spaced street lamps. How long do I take to walk from the first lamp to the last?