This was a problem for our birthday website. Can you use four of these pieces to form a square? How about making a square with all five pieces?

Our 2008 Advent Calendar has a 'Making Maths' activity for every day in the run-up to Christmas.

NRICH December 2006 advent calendar - a new tangram for each day in the run-up to Christmas.

Use your mouse to move the red and green parts of this disc. Can you make images which show the turnings described?

Sort the houses in my street into different groups. Can you do it in any other ways?

Can you fit the tangram pieces into the outline of Granma T?

Complete the squares - but be warned some are trickier than they look!

A game for 1 person. Can you work out how the dice must be rolled from the start position to the finish? Play on line.

How can the same pieces of the tangram make this bowl before and after it was chipped? Use the interactivity to try and work out what is going on!

Use the interactivity or play this dice game yourself. How could you make it fair?

Can you fit the tangram pieces into the outline of Little Fung at the table?

Can you work out what is wrong with the cogs on a UK 2 pound coin?

What happens when you try and fit the triomino pieces into these two grids?

An interactive game for 1 person. You are given a rectangle with 50 squares on it. Roll the dice to get a percentage between 2 and 100. How many squares is this? Keep going until you get 100. . . .

Can you fit the tangram pieces into the outline of this brazier for roasting chestnuts?

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

Twenty four games for the run-up to Christmas.

Investigate how the four L-shapes fit together to make an enlarged L-shape. You could explore this idea with other shapes too.

Can you fit the tangram pieces into the outlines of the chairs?

An interactive activity for one to experiment with a tricky tessellation

Move just three of the circles so that the triangle faces in the opposite direction.

How many right angles can you make using two sticks?

Choose the size of your pegboard and the shapes you can make. Can you work out the strategies needed to block your opponent?

Take it in turns to make a triangle on the pegboard. Can you block your opponent?

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

If you can post the triangle with either the blue or yellow colour face up, how many ways can it be posted altogether?

Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?

Hover your mouse over the counters to see which ones will be removed. Click to remover them. The winner is the last one to remove a counter. How you can make sure you win?

What shaped overlaps can you make with two circles which are the same size? What shapes are 'left over'? What shapes can you make when the circles are different sizes?

Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?

Use the Cuisenaire rods environment to investigate ratio. Can you find pairs of rods in the ratio 3:2? How about 9:6?

Work out the fractions to match the cards with the same amount of money.

A game for 2 people that everybody knows. You can play with a friend or online. If you play correctly you never lose!

Take it in turns to place a domino on the grid. One to be placed horizontally and the other vertically. Can you make it impossible for your opponent to play?

Exchange the positions of the two sets of counters in the least possible number of moves

Can you fit the tangram pieces into the outline of this telephone?

Ahmed has some wooden planks to use for three sides of a rabbit run against the shed. What quadrilaterals would he be able to make with the planks of different lengths?

Find out how we can describe the "symmetries" of this triangle and investigate some combinations of rotating and flipping it.

An interactive game to be played on your own or with friends. Imagine you are having a party. Each person takes it in turns to stand behind the chair where they will get the most chocolate.

A game to be played against the computer, or in groups. Pick a 7-digit number. A random digit is generated. What must you subract to remove the digit from your number? the first to zero wins.

What is the greatest number of squares you can make by overlapping three squares?

A game for 1 or 2 people. Use the interactive version, or play with friends. Try to round up as many counters as possible.

Choose 13 spots on the grid. Can you work out the scoring system? What is the maximum possible score?