A simple visual exploration into halving and doubling.

This article for teachers gives some food for thought when teaching ideas about area.

How would you move the bands on the pegboard to alter these shapes?

Have a good look at these images. Can you describe what is happening? There are plenty more images like this on NRICH's Exploring Squares CD.

You have pitched your tent (the red triangle) on an island. Can you move it to the position shown by the purple triangle making sure you obey the rules?

Grandpa was measuring a rug using yards, feet and inches. Can you help William to work out its area?

Look at the mathematics that is all around us - this circular window is a wonderful example.

Read about David Hilbert who proved that any polygon could be cut up into a certain number of pieces that could be put back together to form any other polygon of equal area.

Use the information on these cards to draw the shape that is being described.

These pieces of wallpaper need to be ordered from smallest to largest. Can you find a way to do it?

How many centimetres of rope will I need to make another mat just like the one I have here?

Nine squares with side lengths 1, 4, 7, 8, 9, 10, 14, 15, and 18 cm can be fitted together to form a rectangle. What are the dimensions of the rectangle?

Can you draw a square in which the perimeter is numerically equal to the area?

What can you say about these shapes? This problem challenges you to create shapes with different areas and perimeters.

What is the largest number of circles we can fit into the frame without them overlapping? How do you know? What will happen if you try the other shapes?

If I use 12 green tiles to represent my lawn, how many different ways could I arrange them? How many border tiles would I need each time?

What is the smallest number of tiles needed to tile this patio? Can you investigate patios of different sizes?

These rectangles have been torn. How many squares did each one have inside it before it was ripped?

What is the largest 'ribbon square' you can make? And the smallest? How many different squares can you make altogether?

A thoughtful shepherd used bales of straw to protect the area around his lambs. Explore how you can arrange the bales.

Investigate all the different squares you can make on this 5 by 5 grid by making your starting side go from the bottom left hand point. Can you find out the areas of all these squares?

This practical challenge invites you to investigate the different squares you can make on a square geoboard or pegboard.

My local DIY shop calculates the price of its windows according to the area of glass and the length of frame used. Can you work out how they arrived at these prices?

In this game for two players, you throw two dice and find the product. How many shapes can you draw on the grid which have that area or perimeter?

How many ways can you find of tiling the square patio, using square tiles of different sizes?

Arrange your fences to make the largest rectangular space you can. Try with four fences, then five, then six etc.

An investigation that gives you the opportunity to make and justify predictions.

Measure problems for inquiring primary learners.

A follow-up activity to Tiles in the Garden.

I cut this square into two different shapes. What can you say about the relationship between them?

Can you put these shapes in order of size? Start with the smallest.

These practical challenges are all about making a 'tray' and covering it with paper.

A task which depends on members of the group noticing the needs of others and responding.

Can you help the children find the two triangles which have the lengths of two sides numerically equal to their areas?

Here are many ideas for you to investigate - all linked with the number 2000.

What happens to the area of a square if you double the length of the sides? Try the same thing with rectangles, diamonds and other shapes. How do the four smaller ones fit into the larger one?

Investigate how this pattern of squares continues. You could measure lengths, areas and angles.

Place four pebbles on the sand in the form of a square. Keep adding as few pebbles as necessary to double the area. How many extra pebbles are added each time?

Investigate the area of 'slices' cut off this cube of cheese. What would happen if you had different-sized block of cheese to start with?

Cut differently-sized square corners from a square piece of paper to make boxes without lids. Do they all have the same volume?

Measure problems for primary learners to work on with others.

What is the total area of the four outside triangles which are outlined in red in this arrangement of squares inside each other?

Measure problems at primary level that may require determination.

Measure problems at primary level that require careful consideration.

What do these two triangles have in common? How are they related?

Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.

What shape has Harry drawn on this clock face? Can you find its area? What is the largest number of square tiles that could cover this area?

Are these statements always true, sometimes true or never true?