Addition and subtraction

  • Magic Letters
    problem
    Favourite

    Magic Letters

    Age
    11 to 14
    Challenge level

    Charlie has made a Magic V. Can you use his example to make some more? And how about Magic Ls, Ns and Ws?

  • Strange Bank Account
    problem
    Favourite

    Strange Bank Account

    Age
    11 to 14
    Challenge level

    Imagine a very strange bank account where you are only allowed to do two things...

  • Up, down, flying around
    game
    Favourite

    Up, Down, Flying Around

    Age
    11 to 14
    Challenge level

    Play this game to learn about adding and subtracting positive and negative numbers

  • Number Daisy
    problem
    Favourite

    Number Daisy

    Age
    11 to 14
    Challenge level

    Can you find six numbers to go in the daisy from which you can make all the numbers from 1 to a number bigger than 25?

  • Cryptarithms
    problem
    Favourite

    Cryptarithms

    Age
    11 to 14
    Challenge level

    Can you crack these cryptarithms?

  • Add to 200
    problem
    Favourite

    Add to 200

    Age
    11 to 14
    Challenge level

    By selecting digits for an addition grid, what targets can you make?

  • Forwards Add Backwards
    problem
    Favourite

    Forwards Add Backwards

    Age
    11 to 14
    Challenge level

    What happens when you add a three digit number to its reverse?

  • Making a difference
    problem
    Favourite

    Making a Difference

    Age
    11 to 14
    Challenge level

    How many different differences can you make?

  • Amazing Card Trick
    problem
    Favourite

    Amazing Card Trick

    Age
    11 to 14
    Challenge level

    How is it possible to predict the card?

  • Weights
    problem
    Favourite

    Weights

    Age
    11 to 14
    Challenge level

    Different combinations of the weights available allow you to make different totals. Which totals can you make?

Displaying 131 - 140 of 346