These activities are part of our Primary collections, which are problems grouped by topic.

Sitting round the party tables

Pairs of numbers
If you have ten counters numbered 1 to 10, how many can you put into pairs that add to 10? Which ones do you have to leave out? Why?

The add and take-away path


Poly plug rectangles
The computer has made a rectangle and will tell you the number of spots it uses in total. Can you find out where the rectangle is?

What was in the box?
This box does something to the numbers that go into it. If you know the numbers that come out, what might be going on inside the box?

Doing and undoing

How do you see it?
Here are some short problems for you to try. Talk to your friends about how you work them out.



How many?
This project challenges you to work out the number of cubes hidden under a cloth. What questions would you like to ask?

What could it be?

Unit differences


Dicey addition
In these addition games, you'll need to think strategically to get closest to the target.

Arranging additions and sorting subtractions

Subtraction slip
Can you spot the mistake in this video? How would you work out the answer to this calculation?

One big triangle
Make one big triangle so the numbers that touch on the small triangles add to 10.


Butterfly flowers
Can you find two butterflies to go on each flower so that the numbers on each pair of butterflies adds to the number on their flower?

What's in a name?

Cuisenaire counting

Number balance
Can you hang weights in the right place to make the the number balance balanced?

Domino sorting
Try grouping the dominoes in the ways described. Are there any left over each time? Can you explain why?

Number lines
Leah and Tom each have a number line. Can you work out where their counters will land?

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

Sort them out (1)

Jumping squares


Birthday cakes
Jack's mum bought some candles to use on his birthday cakes and when his sister was born, she used them on her cakes too. Can you use the information to find out when Kate was born?

Heads and feet
On a farm there were some hens and sheep. Altogether there were 8 heads and 22 feet. How many hens were there?

Ladybirds in the garden
In Sam and Jill's garden there are two sorts of ladybirds with 7 spots or 4 spots. What numbers of total spots can you make?

Eggs in baskets
There are three baskets, a brown one, a red one and a pink one, holding a total of 10 eggs. How many eggs are in each basket?

Secret number
Annie and Ben are playing a game with a calculator. What was Annie's secret number?

Find the difference


Number round up

The Brown family
Use the information about Sally and her brother to find out how many children there are in the Brown family.
