Addition and Subtraction

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?

This big box adds something to any number that goes into it. If you know the numbers that come out, what addition might be going on in the box?

An investigation looking at doing and undoing mathematical operations focusing on doubling, halving, adding and subtracting.

Here are some short problems for you to try. Talk to your friends about how you work them out.

What two-digit numbers can you make with these two dice? What can't you make?

In this calculation, the box represents a missing digit. What could the digit be? What would the solution be in each case?

This challenge is about finding the difference between numbers which have the same tens digit.

Find all the numbers that can be made by adding the dots on two dice.

Who said that adding couldn't be fun?

Order these four calculations from easiest to hardest. How did you decide?

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

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

Can you match pairs of cards which show the same amount?

What do you notice about these squares of numbers? What is the same? What is different?

Here are some rods that are different colours. How could I make a yellow rod using white and red rods?

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

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

A resource to try once children are familiar with number lines, and they have begun to use them for addition. It could be a good way to talk about subtraction. Leah and Tom each have a number line. Can you work out where their counters will land?

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

Can you each work out the number on your card? What do you notice? How could you sort the cards?

Sweets are given out to party-goers in a particular way. Investigate the total number of sweets received by people sitting in different positions.

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?

Two children made up a game as they walked along the garden paths. Can you find out their scores? Can you find some paths of your own?

What could the half time scores have been in these Olympic hockey matches?

In this problem it is not the squares that jump, you do the jumping! The idea is to go round the track in as few jumps as possible.

Noah saw 12 legs walk by into the Ark. How many creatures did he see?

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?

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

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?

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?

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

Place the numbers 1 to 6 in the circles so that each number is the difference between the two numbers just below it.

Using the cards 2, 4, 6, 8, +, - and =, what number statements can you make?

Arrange the numbers 1 to 6 in each set of circles below. The sum of each side of the triangle should equal the number in its centre.

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

As you come down the ladders of the Tall Tower you collect useful spells. Which way should you go to collect the most spells?