Addition and subtraction

  • Scoring with Dice
    problem

    Scoring With Dice

    Age
    7 to 11
    Challenge level
    3 out of 3
    I throw three dice and get 5, 3 and 2. Add the scores on the three dice. What do you get? Now multiply the scores. What do you notice?
  • Seven Square Numbers
    problem

    Seven Square Numbers

    Age
    7 to 11
    Challenge level
    3 out of 3
    Add the sum of the squares of four numbers between 10 and 20 to the sum of the squares of three numbers less than 6 to make the square of another, larger, number.
  • Marvellous Matrix
    problem

    Marvellous Matrix

    Age
    7 to 11
    Challenge level
    3 out of 3
    Follow the directions for circling numbers in the matrix. Add all the circled numbers together. Note your answer. Try again with a different starting number. What do you notice?
  • Rod Measures
    problem

    Rod Measures

    Age
    7 to 11
    Challenge level
    3 out of 3
    Using 3 rods of integer lengths, none longer than 10 units and not using any rod more than once, you can measure all the lengths in whole units from 1 to 10 units. How many ways can you do this?
  • One Million to Seven
    problem

    One Million to Seven

    Age
    7 to 11
    Challenge level
    3 out of 3
    Start by putting one million (1 000 000) into the display of your calculator. Can you reduce this to 7 using just the 7 key and add, subtract, multiply, divide and equals as many times as you like?
  • Some Secret Codes
    problem

    Some Secret Codes

    Age
    7 to 11
    Challenge level
    3 out of 3

    Can you follow the rule to decode the messages?

  • Nice or Nasty for Two
    game

    Nice or Nasty for Two

    Age
    7 to 14
    Challenge level
    1 out of 3

    Some Games That May Be Nice or Nasty for an adult and child. Use your knowledge of place value to beat your opponent.

  • Charitable Pennies
    problem

    Charitable Pennies

    Age
    7 to 14
    Challenge level
    1 out of 3
    Investigate the different ways that fifteen schools could have given money in a charity fundraiser.
  • 3 by 3 Mathdokus
    problem

    3 by 3 Mathdokus

    Age
    7 to 14
    Challenge level
    1 out of 3

    Can you use the clues to complete these 3 by 3 Mathematical Sudokus?

  • Escape from the castle
    problem

    Escape From the Castle

    Age
    7 to 14
    Challenge level
    2 out of 3

    Skippy and Anna are locked in a room in a large castle. The key to that room, and all the other rooms, is a number. The numbers are locked away in a problem. Can you help them to get out?