Addition and subtraction

  • Arrange the Digits
    problem

    Arrange the Digits

    Age
    11 to 14
    Challenge level
    2 out of 3
    Can you arrange the digits 1,2,3,4,5,6,7,8,9 into three 3-digit numbers such that their total is close to 1500?
  • Jugs of Wine
    problem

    Jugs of Wine

    Age
    11 to 14
    Challenge level
    2 out of 3
    You have four jugs of 9, 7, 4 and 2 litres capacity. The 9 litre jug is full of wine, the others are empty. Can you divide the wine into three equal quantities?
  • Homes
    problem

    Homes

    Age
    5 to 7
    Challenge level
    1 out of 3

    Six new homes are being built! They can be detached, semi-detached or terraced houses. How many different combinations of these can you find?

  • Fair Exchange
    problem

    Fair Exchange

    Age
    5 to 7
    Challenge level
    1 out of 3

    In your bank, you have three types of coins. The number of spots shows how much they are worth. Can you choose coins to exchange with the groups given to make the same total?

  • Planet Plex Time
    problem

    Planet Plex Time

    Age
    5 to 7
    Challenge level
    1 out of 3

    On Planet Plex, there are only 6 hours in the day. Can you answer these questions about how Arog the Alien spends his day?

  • Ring of Numbers
    problem

    Ring of Numbers

    Age
    5 to 7
    Challenge level
    1 out of 3

    Choose four of the numbers from 1 to 9 to put in the squares so that the differences between joined squares are odd.

  • Money Line-up
    problem

    Money Line-Up

    Age
    5 to 7
    Challenge level
    1 out of 3

    In this game for two players, the aim is to make a row of four coins which total one dollar.

  • Unit Differences
    problem

    Unit Differences

    Age
    5 to 7
    Challenge level
    1 out of 3

    This challenge is about finding the difference between numbers which have the same tens digit.

  • Shut the Box for Two
    game

    Shut the Box for Two

    Age
    5 to 7
    Challenge level
    1 out of 3

    Shut the Box game for an adult and child. Can you turn over the cards which match the numbers on the dice?

  • Up and Down
    problem

    Up and Down

    Age
    5 to 7
    Challenge level
    2 out of 3
    Sam got into an elevator. He went down five floors, up six floors, down seven floors, then got out on the second floor. On what floor did he get on?