Addition and subtraction

  • Sumo
    game

    Sumo

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

    A number game requiring a strategy.

  • Charitable Pennies
    problem

    Charitable pennies

    Age
    7 to 14
    Challenge level
    filled star empty star empty star
    Investigate the different ways that fifteen schools could have given money in a charity fundraiser.
  • Digit Addition
    problem

    Digit addition

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

    Try out this number trick. What happens with different starting numbers? What do you notice?

  • Sticky Dice
    problem

    Sticky dice

    Age
    7 to 11
    Challenge level
    filled star empty star empty star
    Throughout these challenges, the touching faces of any adjacent dice must have the same number. Can you find a way of making the total on the top come to each number from 11 to 18 inclusive?
  • Folded Number Line
    problem

    Folded number line

    Age
    7 to 11
    Challenge level
    filled star empty star empty star
    When I fold a 0-20 number line, I end up with 'stacks' of numbers on top of each other. These challenges involve varying the length of the number line and investigating the 'stack totals'.
  • Bundles of Cubes
    problem

    Bundles of cubes

    Age
    7 to 11
    Challenge level
    filled star filled star empty star
    Watch this animation. What do you notice? What happens when you try more or fewer cubes in a bundle?
  • Making a difference
    problem

    Making a difference

    Age
    11 to 14
    Challenge level
    filled star empty star empty star
    How many different differences can you make?
  • Six Numbered Cubes
    problem

    Six numbered cubes

    Age
    7 to 11
    Challenge level
    filled star filled star empty star
    This task combines spatial awareness with addition and multiplication.
  • Six Ten Total
    problem

    Six ten total

    Age
    7 to 11
    Challenge level
    filled star filled star empty star
    This challenge combines addition, multiplication, perseverance and even proof.