Activities
Activities
Programme of study statements 
Activities 
A 
B 
C 
D 
read, write and interpret mathematical statements involving addition (+), subtraction (–) and equals (=) signs 




represent and use number bonds and related subtraction facts within 20 




add and subtract onedigit and twodigit numbers to 20, including zero 




solve onestep problems that involve addition and subtraction, using concrete objects and pictorial representations, and missing number problems such as
7 = ? – 9 




Activity set A
It is really important that the children understand the equals sign as a sign of equivalence, that what is on one side of it has the same value as what is on the other. Many children develop the misconception that the answer to a calculation is on the righthand side of the equals sign. To ensure that they don’t develop this misconception you could give them a set of balance scales and some interlocking cubes. They can then explore adding different numbers of cubes on each side of the balance to find out what happens. For example, if they put 5 cubes on one side and 10 on the other, the scales won’t balance. They can then find out how many they need to add to the side with 5 cubes so that they balance. They could record this in a number sentence such as, 5 + 5 = 10 or 10 = 5 + 5.
They could explore subtraction in the same way, for example, they put 20 cubes on one side and 12 on the other. They then find out how many they should take away from the 20 cubes so that the scales balance with 12 cubes on each side. Again they could record this in a number sentence such as, 20 – 8 = 12
You could give the children missing number sentences and ask them to find the solutions using the scales, for example:

? + 3 = 12 (put 12 cubes on one side of the balance and 3 on the other, add cubes to the 3 until they balance)

8 + ? = 15 (put 15 cubes on one side of the balance and 8 on the other, add cubes to the 8 until they balance)

20  ? = 13 (put 20 cubes on one side of the balance and 13 on the other, take cubes from the 20 until they balance)

? – 4 = 7 (put 7 cubes on one side of the balance and another amount on the other, they explore how many they need so that when they take 4 away the scales will balance)
When the children are confident at doing this, they could then use the bar model and draw the problem, for example:
Activity set B
The children need to learn number bonds or number pairs for all numbers to 20 not simply those that make 10 and 20.
You could give them counters or cubes for the number you wish to focus on and ask the children to put them into two groups. How many different groups can they make. They would need to keep track of their work by writing number sentences, for example:
Making 7
1 + 6 = 7, 2 + 5 = 7, 3 + 4 = 7, 4 + 3 = 7 and so on…
You might be interested in using ‘Number pair Love Hearts’ from the "What makes a good resource?" section of the NCETM website. The instructions and downloadable resources are available. You could adapt this for any numbers to 20.
Activity set C
Give the children calculations to solve that involve adding and subtracting numbers to 20. They should use manipulatives, such as bead strings, cubes or counters, so that their experiences are concrete. Alongside these encourage them to write the appropriate number sentences. You could also encourage them to draw number lines to show what they have done.
You could ask them to write the age they are on a piece of paper. They then try to make their age using as many different additions and subtractions as they can. Here is an example:
Activity set D
You could give the children problems such as these to solve:

Harry had 6 marbles. His friend gave him 12 more. How many marbles does Harry have now?
They could solve these using the bar model as described for the first requirement, for example:
6 + 12
The children could place the correct number of objects in the two numbered sections of the bar and then count them all to find the missing number.

Holly 13 biscuits. She ate 5. How many does she have left
135
You could ask them ‘What number am I thinking of?’ type questions, for example:

I am thinking of a number .When I add 3, I get 8. What number am I thinking of?

I am thinking of a number. When I take away 4, I get 7. What number am I thinking of?
You could use straws, dice and elastic bands and play a game that will introduce the children to the concept of exchange:

Throw a dice. Collect that number of straws.

When you have 10 make a bundle using an elastic band.

The winner is the first player to make more than 20.
This can also be done for subtraction:

Take two bundles of straws.

Throw the dice. Take that number of straws away. (The children will need to ‘unbundle’ one bundle)

The winner is the first player to lose all their straws.