These practical challenges are all about making a 'tray' and covering it with paper.
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?
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?
Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
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?
Can you make the most extraordinary, the most amazing, the most unusual patterns/designs from these triangles which are made in a special way?
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.
What is the smallest cuboid that you can put in this box so that you cannot fit another that's the same into it?
This activity investigates how you might make squares and pentominoes from Polydron.
How many triangles can you make on the 3 by 3 pegboard?
Are all the possible combinations of two shapes included in this set of 27 cards? How do you know?
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.
An activity making various patterns with 2 x 1 rectangular tiles.
In this challenge, you will work in a group to investigate circular fences enclosing trees that are planted in square or triangular arrangements.
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?
How many models can you find which obey these rules?
Can you order pictures of the development of a frog from frogspawn and of a bean seed growing into a plant?
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?
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 can you put five cereal packets together to make different shapes if you must put them face-to-face?
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?
Can you make dice stairs using the rules stated? How do you know you have all the possible stairs?
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.
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?
This practical investigation invites you to make tessellating shapes in a similar way to the artist Escher.
Arrange your fences to make the largest rectangular space you can. Try with four fences, then five, then six etc.
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.
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 create more models that follow these rules?
Watch the video to see how to fold a square of paper to create a flower. What fraction of the piece of paper is the small triangle?
What are the next three numbers in this sequence? Can you explain why are they called pyramid numbers?
This practical problem challenges you to create shapes and patterns with two different types of triangle. You could even try overlapping them.
For this task, you'll need an A4 sheet and two A5 transparent sheets. Decide on a way of arranging the A5 sheets on top of the A4 sheet and explore ...
What do these two triangles have in common? How are they related?
Make new patterns from simple turning instructions. You can have a go using pencil and paper or with a floor robot.
A brief video looking at how you can sometimes use symmetry to distinguish knots. Can you use this idea to investigate the differences between the granny knot and the reef knot?
How many different cuboids can you make when you use four CDs or DVDs? How about using five, then six?
Our 2008 Advent Calendar has a 'Making Maths' activity for every day in the run-up to Christmas.
Can you make the birds from the egg tangram?
How is it possible to predict the card?
How do you know if your set of dominoes is complete?
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?
NRICH December 2006 advent calendar - a new tangram for each day in the run-up to Christmas.
A group of children are discussing the height of a tall tree. How would you go about finding out its height?
Delight your friends with this cunning trick! Can you explain how it works?
Cut a square of paper into three pieces as shown. Now,can you use the 3 pieces to make a large triangle, a parallelogram and the square again?
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?
Paint a stripe on a cardboard roll. Can you predict what will happen when it is rolled across a sheet of paper?
Can you visualise what shape this piece of paper will make when it is folded?
Make a flower design using the same shape made out of different sizes of paper.