Can you make the most extraordinary, the most amazing, the most unusual patterns/designs from these triangles which are made in a special way?
How many triangles can you make on the 3 by 3 pegboard?
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?
These practical challenges are all about making a 'tray' and covering it with paper.
Can you make dice stairs using the rules stated? How do you know you have all the possible stairs?
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?
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?
How many models can you find which obey these rules?
What do these two triangles have in common? How are they related?
How can you put five cereal packets together to make different shapes if you must put them face-to-face?
If you split the square into these two pieces, it is possible to fit the pieces together again to make a new shape. How many new shapes can you make?
What is the smallest cuboid that you can put in this box so that you cannot fit another that's the same into it?
Can you order pictures of the development of a frog from frogspawn and of a bean seed growing into a plant?
These pictures show squares split into halves. Can you find other ways?
Make a chair and table out of interlocking cubes, making sure that the chair fits under the table!
Make new patterns from simple turning instructions. You can have a go using pencil and paper or with a floor robot.
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?
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?
In this town, houses are built with one room for each person. There are some families of seven people living in the town. In how many different ways can they build their houses?
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.
How can you arrange the 5 cubes so that you need the smallest number of Brush Loads of paint to cover them? Try with other numbers of cubes as well.
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.
Try continuing these patterns made from triangles. Can you create your own repeating pattern?
What is the largest number of circles we can fit into the frame without them overlapping? How do you know? What will happen if you try the other shapes?
This activity investigates how you might make squares and pentominoes from Polydron.
Arrange your fences to make the largest rectangular space you can. Try with four fences, then five, then six etc.
This problem focuses on Dienes' Logiblocs. What is the same and what is different about these pairs of shapes? Can you describe the shapes in the picture?
Explore the triangles that can be made with seven sticks of the same length.
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.
This practical problem challenges you to create shapes and patterns with two different types of triangle. You could even try overlapping them.
Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
How do you know if your set of dominoes is complete?
Use the three triangles to fill these outline shapes. Perhaps you can create some of your own shapes for a friend to fill?
Here are some ideas to try in the classroom for using counters to investigate number patterns.
Is there a best way to stack cans? What do different supermarkets do? How high can you safely stack the cans?
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?
An activity making various patterns with 2 x 1 rectangular tiles.
Are all the possible combinations of two shapes included in this set of 27 cards? How do you know?
Follow these instructions to make a five-pointed snowflake from a square of paper.
Can you see which tile is the odd one out in this design? Using the basic tile, can you make a repeating pattern to decorate our wall?
Kaia is sure that her father has worn a particular tie twice a week in at least five of the last ten weeks, but her father disagrees. Who do you think is right?
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.
Surprise your friends with this magic square trick.
Did you know mazes tell stories? Find out more about mazes and make one of your own.
Can you split each of the shapes below in half so that the two parts are exactly the same?
Have a go at making a few of these shapes from paper in different sizes. What patterns can you create?
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.
Ideas for practical ways of representing data such as Venn and Carroll diagrams.