Delight your friends with this cunning trick! Can you explain how it works?

I start with a red, a green and a blue marble. I can trade any of my marbles for two others, one of each colour. Can I end up with five more blue marbles than red after a number of such trades?

I start with a red, a blue, a green and a yellow marble. I can trade any of my marbles for three others, one of each colour. Can I end up with exactly two marbles of each colour?

How can you make an angle of 60 degrees by folding a sheet of paper twice?

These are pictures of the sea defences at New Brighton. Can you work out what a basic shape might be in both images of the sea wall and work out a way they might fit together?

Here is a solitaire type environment for you to experiment with. Which targets can you reach?

A jigsaw where pieces only go together if the fractions are equivalent.

Here is a chance to create some attractive images by rotating shapes through multiples of 90 degrees, or 30 degrees, or 72 degrees or...

The Tower of Hanoi is an ancient mathematical challenge. Working on the building blocks may help you to explain the patterns you notice.

Use the interactivity to play two of the bells in a pattern. How do you know when it is your turn to ring, and how do you know which bell to ring?

Imagine you have an unlimited number of four types of triangle. How many different tetrahedra can you make?

Use the interactivity to listen to the bells ringing a pattern. Now it's your turn! Play one of the bells yourself. How do you know when it is your turn to ring?

The triangle ABC is equilateral. The arc AB has centre C, the arc BC has centre A and the arc CA has centre B. Explain how and why this shape can roll along between two parallel tracks.

Interior angles can help us to work out which polygons will tessellate. Can we use similar ideas to predict which polygons combine to create semi-regular solids?

Generate three random numbers to determine the side lengths of a triangle. What triangles can you draw?

Use the tangram pieces to make our pictures, or to design some of your own!

This article for pupils gives an introduction to Celtic knotwork patterns and a feel for how you can draw them.

Move your counters through this snake of cards and see how far you can go. Are you surprised by where you end up?

It might seem impossible but it is possible. How can you cut a playing card to make a hole big enough to walk through?

You could use just coloured pencils and paper to create this design, but it will be more eye-catching if you can get hold of hammer, nails and string.

In this article for teachers, Bernard uses some problems to suggest that once a numerical pattern has been spotted from a practical starting point, going back to the practical can help explain. . . .

This article for students gives some instructions about how to make some different braids.

A game to make and play based on the number line.

Which of the following cubes can be made from these nets?

Make your own double-sided magic square. But can you complete both sides once you've made the pieces?

These models have appeared around the Centre for Mathematical Sciences. Perhaps you would like to try to make some similar models of your own.

Can you puzzle out what sequences these Logo programs will give? Then write your own Logo programs to generate sequences.

As part of Liverpool08 European Capital of Culture there were a huge number of events and displays. One of the art installations was called "Turning the Place Over". Can you find our how it works?

How many differently shaped rectangles can you build using these equilateral and isosceles triangles? Can you make a square?

Make some celtic knot patterns using tiling techniques

Galileo, a famous inventor who lived about 400 years ago, came up with an idea similar to this for making a time measuring instrument. Can you turn your pendulum into an accurate minute timer?

Make a clinometer and use it to help you estimate the heights of tall objects.

Exploring balance and centres of mass can be great fun. The resulting structures can seem impossible. Here are some images to encourage you to experiment with non-breakable objects of your own.

Make an equilateral triangle by folding paper and use it to make patterns of your own.

Here is a chance to create some Celtic knots and explore the mathematics behind them.

Can you use small coloured cubes to make a 3 by 3 by 3 cube so that each face of the bigger cube contains one of each colour?

Time for a little mathemagic! Choose any five cards from a pack and show four of them to your partner. How can they work out the fifth?

What shape and size of drinks mat is best for flipping and catching?

What shapes should Elly cut out to make a witch's hat? How can she make a taller hat?

What shape would fit your pens and pencils best? How can you make it?

How does the time of dawn and dusk vary? What about the Moon, how does that change from night to night? Is the Sun always the same? Gather data to help you explore these questions.

Design and construct a prototype intercooler which will satisfy agreed quality control constraints.

Can Jo make a gym bag for her trainers from the piece of fabric she has?

Build a scaffold out of drinking-straws to support a cup of water

More Logo for beginners. Learn to calculate exterior angles and draw regular polygons using procedures and variables.

Using your knowledge of the properties of numbers, can you fill all the squares on the board?

A description of how to make the five Platonic solids out of paper.

A game in which players take it in turns to choose a number. Can you block your opponent?