How many different ways can you find to join three equilateral triangles together? Can you convince us that you have found them all?
Can you find all the different ways of lining up these Cuisenaire rods?
Can you put the numbers from 1 to 15 on the circles so that no consecutive numbers lie anywhere along a continuous straight line?
How many different triangles can you draw on the dotty grid which each have one dot in the middle?
How many different triangles can you make on a circular pegboard that has nine pegs?
How many different rhythms can you make by putting two drums on the wheel?
Use the interactivity to help get a feel for this problem and to find out all the possible ways the balls could land.
Use the clues to colour each square.
How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?
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....?
Can you put the numbers 1 to 8 into the circles so that the four calculations are correct?
Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.
Cut four triangles from a square as shown in the picture. How many different shapes can you make by fitting the four triangles back together?
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?
You have 4 red and 5 blue counters. How many ways can they be placed on a 3 by 3 grid so that all the rows columns and diagonals have an even number of red counters?
Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
A tetromino is made up of four squares joined edge to edge. Can this tetromino, together with 15 copies of itself, be used to cover an eight by eight chessboard?
Can you cover the camel with these pieces?
What happens when you try and fit the triomino pieces into these two grids?
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?
Terry and Ali are playing a game with three balls. Is it fair that Terry wins when the middle ball is red?
Sort the houses in my street into different groups. Can you do it in any other ways?
If you can post the triangle with either the blue or yellow colour face up, how many ways can it be posted altogether?
What do the numbers shaded in blue on this hundred square have in common? What do you notice about the pink numbers? How about the shaded numbers in the other squares?
Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?
Use your mouse to move the red and green parts of this disc. Can you make images which show the turnings described?
Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.
Can you work out how to balance this equaliser? You can put more than one weight on a hook.
Here are some rods that are different colours. How could I make a dark green rod using yellow and white rods?
Explore the different tunes you can make with these five gourds. What are the similarities and differences between the two tunes you are given?
Can you make a train the same length as Laura's but using three differently coloured rods? Is there only one way of doing it?
This problem is based on a code using two different prime numbers less than 10. You'll need to multiply them together and shift the alphabet forwards by the result. Can you decipher the code?
Find out how we can describe the "symmetries" of this triangle and investigate some combinations of rotating and flipping it.
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
Try out the lottery that is played in a far-away land. What is the chance of winning?
Can you find all the different triangles on these peg boards, and find their angles?
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
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.
Find out what a "fault-free" rectangle is and try to make some of your own.
Investigate the different sounds you can make by putting the owls and donkeys on the wheel.
Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.
In your bank, you have three types of coins. The number of spots shows how much they are worth. Can you choose coins to exchange with the groups given to make the same total?
There are nine teddies in Teddy Town - three red, three blue and three yellow. There are also nine houses, three of each colour. Can you put them on the map of Teddy Town according to the rules?
Can you fit the tangram pieces into the outline of Little Fung at the table?
Can you fit the tangram pieces into the outline of this brazier for roasting chestnuts?
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?
Can you fit the tangram pieces into the outlines of these people?
Can you fit the tangram pieces into the outline of the child walking home from school?
An interactive activity for one to experiment with a tricky tessellation