Let's say you can only use two different lengths - 2 units and 4 units. Using just these 2 lengths as the edges how many different cuboids can you make?
How can you put five cereal packets together to make different shapes if you must put them face-to-face?
What is the smallest cuboid that you can put in this box so that you cannot fit another that's the same into it?
How many models can you find which obey these rules?
How many different cuboids can you make when you use four CDs or DVDs? How about using five, then six?
The ancient Egyptians were said to make right-angled triangles using a rope with twelve equal sections divided by knots. What other triangles could you make if you had a rope like this?
Take 5 cubes of one colour and 2 of another colour. How many different ways can you join them if the 5 must touch the table and the 2 must not touch the table?
This practical investigation invites you to make tessellating shapes in a similar way to the artist Escher.
Can you create more models that follow these rules?
How many triangles can you make on the 3 by 3 pegboard?
We went to the cinema and decided to buy some bags of popcorn so we asked about the prices. Investigate how much popcorn each bag holds so find out which we might have bought.
Using different numbers of sticks, how many different triangles are you able to make? Can you make any rules about the numbers of sticks that make the most triangles?
Can you make the most extraordinary, the most amazing, the most unusual patterns/designs from these triangles which are made in a special way?
Kate has eight multilink cubes. She has two red ones, two yellow, two green and two blue. She wants to fit them together to make a cube so that each colour shows on each face just once.
Take a rectangle of paper and fold it in half, and half again, to make four smaller rectangles. How many different ways can you fold it up?
Arrange 9 red cubes, 9 blue cubes and 9 yellow cubes into a large 3 by 3 cube. No row or column of cubes must contain two cubes of the same colour.
Are all the possible combinations of two shapes included in this set of 27 cards? How do you know?
An activity making various patterns with 2 x 1 rectangular tiles.
These practical challenges are all about making a 'tray' and covering it with paper.
In how many ways can you fit two of these yellow triangles together? Can you predict the number of ways two blue triangles can be fitted together?
Make a cube out of straws and have a go at this practical challenge.
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?
Can you fit the tangram pieces into the outlines of Mai Ling and Chi Wing?
Can you fit the tangram pieces into the outlines of the candle and sundial?
Can you fit the tangram pieces into the outlines of the workmen?
Can you fit the tangram pieces into the outline of this shape. How would you describe it?
Can you fit the tangram pieces into the outline of Little Ming and Little Fung dancing?
Can you fit the tangram pieces into the outline of this plaque design?
Can you fit the tangram pieces into the outline of these rabbits?
Can you fit the tangram pieces into the outline of the telescope and microscope?
Can you fit the tangram pieces into the outline of this goat and giraffe?
Paint a stripe on a cardboard roll. Can you predict what will happen when it is rolled across a sheet of paper?
What is the greatest number of counters you can place on the grid below without four of them lying at the corners of a square?
Did you know mazes tell stories? Find out more about mazes and make one of your own.
Can you fit the tangram pieces into the outlines of the chairs?
Exploring and predicting folding, cutting and punching holes and making spirals.
Can you fit the tangram pieces into the outlines of the lobster, yacht and cyclist?
Looking at the picture of this Jomista Mat, can you decribe what you see? Why not try and make one yourself?
Use the lines on this figure to show how the square can be divided into 2 halves, 3 thirds, 6 sixths and 9 ninths.
This problem invites you to build 3D shapes using two different triangles. Can you make the shapes from the pictures?
Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
Can you logically construct these silhouettes using the tangram pieces?
Can you work out what shape is made by folding in this way? Why not create some patterns using this shape but in different sizes?
NRICH December 2006 advent calendar - a new tangram for each day in the run-up to Christmas.
Make a flower design using the same shape made out of different sizes of paper.
This practical problem challenges you to create shapes and patterns with two different types of triangle. You could even try overlapping them.
Can you fit the tangram pieces into the outline of the child walking home from school?
Can you visualise what shape this piece of paper will make when it is folded?
Can you fit the tangram pieces into the outline of Wai Ping, Wah Ming and Chi Wing?
Have you noticed that triangles are used in manmade structures? Perhaps there is a good reason for this? 'Test a Triangle' and see how rigid triangles are.