This challenge involves eight three-cube models made from interlocking cubes. Investigate different ways of putting the models together then compare your constructions.
How many models can you find which obey these rules?
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?
Investigate the number of paths you can take from one vertex to another in these 3D shapes. Is it possible to take an odd number and an even number of paths to the same vertex?
How many different cuboids can you make when you use four CDs or DVDs? How about using five, then six?
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?
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 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.
In this investigation, you must try to make houses using cubes. If the base must not spill over 4 squares and you have 7 cubes which stand for 7 rooms, what different designs can you come up with?
How many shapes can you build from three red and two green cubes? Can you use what you've found out to predict the number for four red and two green?
This challenge is to design different step arrangements, which must go along a distance of 6 on the steps and must end up at 6 high.
Use the interactivity to investigate what kinds of triangles can be drawn on peg boards with different numbers of pegs.
What is the largest cuboid you can wrap in an A3 sheet of 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?
Can you find ways of joining cubes together so that 28 faces are visible?
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.
Arrange your fences to make the largest rectangular space you can. Try with four fences, then five, then six etc.
How can you arrange these 10 matches in four piles so that when you move one match from three of the piles into the fourth, you end up with the same arrangement?
A thoughtful shepherd used bales of straw to protect the area around his lambs. Explore how you can arrange the bales.
How many different ways can you find of fitting five hexagons together? How will you know you have found all the ways?
We need to wrap up this cube-shaped present, remembering that we can have no overlaps. What shapes can you find to use?
How many faces can you see when you arrange these three cubes in different ways?
Suppose there is a train with 24 carriages which are going to be put together to make up some new trains. Can you find all the ways that this can be done?
Have a go at this 3D extension to the Pebbles problem.
Can you create more models that follow these rules?
Investigate the different ways you could split up these rooms so that you have double the number.
If we had 16 light bars which digital numbers could we make? How will you know you've found them all?
It starts quite simple but great opportunities for number discoveries and patterns!
Investigate the area of 'slices' cut off this cube of cheese. What would happen if you had different-sized block of cheese to start with?
In how many ways can you stack these rods, following the rules?
How could you put eight beanbags in the hoops so that there are four in the blue hoop, five in the red and six in the yellow? Can you find all the ways of doing this?
This tricky challenge asks you to find ways of going across rectangles, going through exactly ten squares.
What happens if you join every second point on this circle? How about every third point? Try with different steps and see if you can predict what will happen.
Why does the tower look a different size in each of these pictures?
Polygonal numbers are those that are arranged in shapes as they enlarge. Explore the polygonal numbers drawn here.
Suppose we allow ourselves to use three numbers less than 10 and multiply them together. How many different products can you find? How do you know you've got them all?
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?
Explore one of these five pictures.
Explore Alex's number plumber. What questions would you like to ask? Don't forget to keep visiting NRICH projects site for the latest developments and questions.
I like to walk along the cracks of the paving stones, but not the outside edge of the path itself. How many different routes can you find for me to take?
How many different shaped boxes can you design for 36 sweets in one layer? Can you arrange the sweets so that no sweets of the same colour are next to each other in any direction?
This problem is based on the story of the Pied Piper of Hamelin. Investigate the different numbers of people and rats there could have been if you know how many legs there are altogether!
In this investigation we are going to count the number of 1s, 2s, 3s etc in numbers. Can you predict what will happen?
Can you continue this pattern of triangles and begin to predict how many sticks are used for each new "layer"?
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?
Make new patterns from simple turning instructions. You can have a go using pencil and paper or with a floor robot.
This challenge involves calculating the number of candles needed on birthday cakes. It is an opportunity to explore numbers and discover new things.
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 smallest number of tiles needed to tile this patio? Can you investigate patios of different sizes?
Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.