Starting with the number 180, take away 9 again and again, joining up the dots as you go. Watch out - don't join all the dots!

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

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

An interactive activity for one to experiment with a tricky tessellation

Train game for an adult and child. Who will be the first to make the train?

A game for 2 people that can be played on line or with pens and paper. Combine your knowledege of coordinates with your skills of strategic thinking.

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. . . .

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?

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

How have the numbers been placed in this Carroll diagram? Which labels would you put on each row and column?

Can you complete this jigsaw of the multiplication square?

Incey Wincey Spider game for an adult and child. Will Incey get to the top of the drainpipe?

Use the interactivity to find out how many quarter turns the man must rotate through to look like each of the pictures.

In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?

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.

If you have only four weights, where could you place them in order to balance this equaliser?

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

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

Can you make a cycle of pairs that add to make a square number using all the numbers in the box below, once and once only?

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

Can you work out how to balance this equaliser? You can put more than one weight on a hook.

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

Imagine a wheel with different markings painted on it at regular intervals. Can you predict the colour of the 18th mark? The 100th mark?

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?

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

Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?

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?

Play this well-known game against the computer where each player is equally likely to choose scissors, paper or rock. Why not try the variations too?

What are the coordinates of the coloured dots that mark out the tangram? Try changing the position of the origin. What happens to the coordinates now?

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

Use the interactivities to fill in these Carroll diagrams. How do you know where to place the numbers?

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?

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

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

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

Is it possible to place 2 counters on the 3 by 3 grid so that there is an even number of counters in every row and every column? How about if you have 3 counters or 4 counters or....?

Arrange any number of counters from these 18 on the grid to make a rectangle. What numbers of counters make rectangles? How many different rectangles can you make with each number of counters?

Start by putting one million (1 000 000) into the display of your calculator. Can you reduce this to 7 using just the 7 key and add, subtract, multiply, divide and equals as many times as you like?