Mental calculations

  • Days and Dates
    problem

    Days and dates

    Age
    11 to 14
    Challenge level
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    Investigate how you can work out what day of the week your birthday will be on next year, and the year after...

  • Consecutive Seven
    problem

    Consecutive seven

    Age
    11 to 14
    Challenge level
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    Can you arrange these numbers into 7 subsets, each of three numbers, so that when the numbers in each are added together, they make seven consecutive numbers?

  • Going round in circles
    problem

    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

    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

    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

    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: x2 and -5. What do you think?

  • Overlaps
    problem

    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?

  • Bochap Sudoku
    problem

    Bochap Sudoku

    Age
    11 to 16
    Challenge level
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    This Sudoku combines all four arithmetic operations.

  • Power Countdown
    problem

    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.