Addition and subtraction

  • On Target
    problem

    On Target

    Age
    7 to 11
    Challenge level
    3 out of 3
    You have 5 darts and your target score is 44. How many different ways could you score 44?
  • Let's Face It
    problem

    Let's Face It

    Age
    7 to 11
    Challenge level
    3 out of 3
    In this problem you have to place four by four magic squares on the faces of a cube so that along each edge of the cube the numbers match.
  • The 24 Game
    problem

    The 24 Game

    Age
    7 to 11
    Challenge level
    3 out of 3
    There are over sixty different ways of making 24 by adding, subtracting, multiplying and dividing all four numbers 4, 6, 6 and 8 (using each number only once). How many can you find?
  • Sam's Quick Sum
    problem

    Sam's Quick Sum

    Age
    7 to 11
    Challenge level
    3 out of 3
    What is the sum of all the three digit whole numbers?
  • Oddly
    problem

    Oddly

    Age
    7 to 11
    Challenge level
    3 out of 3
    Find the sum of all three-digit numbers each of whose digits is odd.
  • Difference
    problem

    Difference

    Age
    7 to 11
    Challenge level
    3 out of 3

    Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.

  • Pouring the Punch Drink
    problem

    Pouring the Punch Drink

    Age
    7 to 11
    Challenge level
    3 out of 3

    There are 4 jugs which hold 9 litres, 7 litres, 4 litres and 2 litres. Find a way to pour 9 litres of drink from one jug to another until you are left with exactly 3 litres in three of the jugs.

  • 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?