Mental calculations

  • problem

    Noah

    Age
    5 to 7
    Challenge level
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    Noah saw 12 legs walk by into the Ark. How many creatures did he see?

  • problem

    Maze 100

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

    Can you go through this maze so that the numbers you pass add to exactly 100?

  • I'm Eight
    problem

    I'm eight

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

    Find a great variety of ways of asking questions which make 8.

  • Roll these Dice
    problem

    Roll these dice

    Age
    7 to 11
    Challenge level
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    Roll two red dice and a green dice. Add the two numbers on the red dice and take away the number on the green. What are all the different possible answers?

  • Integrated sums sudoku
    page

    Integrated sums Sudoku

    The puzzle can be solved with the help of small clue-numbers which are either placed on the border lines between selected pairs of neighbouring squares of the grid or placed after slash marks on the intersections between two diagonally adjacent squares.

  • Clever Carl
    article

    Clever Carl

    What would you do if your teacher asked you add all the numbers from 1 to 100? Find out how Carl Gauss responded when he was asked to do just that.

  • Dicey Operations
    game
    Favourite

    Dicey operations

    Age
    7 to 14
    Challenge level
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    In these addition and subtraction games, you'll need to think strategically to get closest to the target.

  • Countdown
    game
    Favourite

    Countdown

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

    Here is a chance to play a version of the classic Countdown Game.

  • Calculator Bingo
    game

    Calculator bingo

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

    This is a game for two players. What must you subtract to remove the rolled digit from your number? The first to zero wins!

  • Wild Jack
    game

    Wild Jack

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

    A game for 2 or more players with a pack of cards. Practise your skills of addition, subtraction, multiplication and division to hit the target score.