Addition and Subtraction

problem

Favourite

Subtraction Surprise

Age

7 to 14

Challenge level

Try out some calculations. Are you surprised by the results?

problem

Favourite

Buying a Balloon

Age

7 to 11

Challenge level

Lolla bought a balloon at the circus. She gave the clown six coins to pay for it. What could Lolla have paid for the balloon?

problem

Favourite

Space distances

Age

7 to 11

Challenge level

This task focuses on distances travelled by the asteroid Florence. It's an opportunity to work with very large numbers.

problem

Favourite

Super Shapes

Age

7 to 11

Challenge level

The value of the circle changes in each of the following problems. Can you discover its value in each problem?

problem

Favourite

Strike it Out

Age

5 to 11

Challenge level

Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.

problem

Favourite

Fifteen cards

Age

7 to 11

Challenge level

Can you use the information to find out which cards I have used?

problem

Favourite

Consecutive Numbers

Age

7 to 14

Challenge level

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

problem

Favourite

Play to 37

Age

7 to 11

Challenge level

In this game for two players, the idea is to take it in turns to choose 1, 3, 5 or 7. The winner is the first to make the total 37.

problem

Favourite

Build it up

Age

7 to 11

Challenge level

Can you find all the ways to get 15 at the top of this triangle of numbers? Many opportunities to work in different ways.

problem

Favourite

What Distance?

Age

7 to 11

Challenge level

Can you use addition and subtraction to answer these questions about real-life distances?

problem

Favourite

Ordering Journeys

Age

7 to 11

Challenge level

How would you put these journey lengths in order?

problem

Favourite

Amy's Dominoes

Age

7 to 11

Challenge level

Amy has a box containing domino pieces but she does not think it is a complete set. Which of her domino pieces are missing?

problem

Favourite

Twenty Divided into Six

Age

7 to 11

Challenge level

Katie had a pack of 20 cards numbered from 1 to 20. She arranged the cards into 6 unequal piles where each pile added to the same total. What was the total and how could this be done?

problem

Favourite

Reach 100

Age

7 to 11

Challenge level

Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.

problem

Favourite

Sealed Solution

Age

7 to 11

Challenge level

Ten cards are put into five envelopes so that there are two cards in each envelope. The sum of the numbers inside it is written on each envelope. What numbers could be inside the envelopes?

problem

Favourite

Got It

Age

7 to 14

Challenge level

A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.

problem

Favourite

Finding Fifteen

Age

7 to 11

Challenge level

Tim had nine cards each with a different number from 1 to 9 on it. How could he have put them into three piles so that the total in each pile was 15?

problem

Favourite

Roll these Dice

Age

7 to 11

Challenge level

Roll two red dice and a green dice. Add the two numbers on the red dice and take away the number on the green. What are all the different possible answers?