Have a go at this 3D extension to the Pebbles problem.
You have been given three shapes made out of sponge: a sphere, a cylinder and a cone. Your challenge is to find out how to cut them to make different shapes for printing.
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?
What is the smallest cuboid that you can put in this box so that you cannot fit another that's the same into it?
What is the total area of the four outside triangles which are outlined in red in this arrangement of squares inside each other?
Choose a box and work out the smallest rectangle of paper needed to wrap it so that it is completely covered.
What shape has Harry drawn on this clock face? Can you find its area? What is the largest number of square tiles that could cover this area?
How can you paint the faces of these eight cubes so they can be put together to make a 2 x 2 x 2 cube that is green all over AND a 2 x 2 x 2 cube that is yellow all over?
How many different ways can you find of fitting five hexagons together? How will you know you have found all the ways?
A dog is looking for a good place to bury his bone. Can you work out where he started and ended in each case? What possible routes could he have taken?
Can you find ways of joining cubes together so that 28 faces are visible?
Can you cut up a square in the way shown and make the pieces into a triangle?
A game has a special dice with a colour spot on each face. These three pictures show different views of the same dice. What colour is opposite blue?
Make a cube out of straws and have a go at this practical challenge.
Exploring and predicting folding, cutting and punching holes and making spirals.
What is the greatest number of squares you can make by overlapping three squares?
This practical problem challenges you to make quadrilaterals with a loop of string. You'll need some friends to help!
Imagine a 3 by 3 by 3 cube made of 9 small cubes. Each face of the large cube is painted a different colour. How many small cubes will have two painted faces? Where are they?
How will you go about finding all the jigsaw pieces that have one peg and one hole?
This challenge involves eight three-cube models made from interlocking cubes. Investigate different ways of putting the models together then compare your constructions.
This task, written for the National Young Mathematicians' Award 2016, involves open-topped boxes made with interlocking cubes. Explore the number of units of paint that are needed to cover the boxes. . . .
Here are the six faces of a cube - in no particular order. Here are three views of the cube. Can you deduce where the faces are in relation to each other and record them on the net of this cube?
10 space travellers are waiting to board their spaceships. There are two rows of seats in the waiting room. Using the rules, where are they all sitting? Can you find all the possible ways?
Swap the stars with the moons, using only knights' moves (as on a chess board). What is the smallest number of moves possible?
I've made some cubes and some cubes with holes in. This challenge invites you to explore the difference in the number of small cubes I've used. Can you see any patterns?
In each of the pictures the invitation is for you to: Count what you see. Identify how you think the pattern would continue.
Paint a stripe on a cardboard roll. Can you predict what will happen when it is rolled across a sheet of paper?
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?
Reasoning about the number of matches needed to build squares that share their sides.
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?
Can you cut a regular hexagon into two pieces to make a parallelogram? Try cutting it into three pieces to make a rhombus!
A magician took a suit of thirteen cards and held them in his hand face down. Every card he revealed had the same value as the one he had just finished spelling. How did this work?
Where can you put the mirror across the square so that you can still "see" the whole square? How many different positions are possible?
How many DIFFERENT quadrilaterals can be made by joining the dots on the 8-point circle?
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?
This problem invites you to build 3D shapes using two different triangles. Can you make the shapes from the pictures?
Use the lines on this figure to show how the square can be divided into 2 halves, 3 thirds, 6 sixths and 9 ninths.
What shape is made when you fold using this crease pattern? Can you make a ring design?
Can you shunt the trucks so that the Cattle truck and the Sheep truck change places and the Engine is back on the main line?
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?
How many different triangles can you make on a circular pegboard that has nine pegs?
Here you see the front and back views of a dodecahedron. Each vertex has been numbered so that the numbers around each pentagonal face add up to 65. Can you find all the missing numbers?
Make a flower design using the same shape made out of different sizes of paper.
Can you visualise what shape this piece of paper will make when it is folded?
Bilbo goes on an adventure, before arriving back home. Using the information given about his journey, can you work out where Bilbo lives?
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 ...
How many different cuboids can you make when you use four CDs or DVDs? How about using five, then six?
Looking at the picture of this Jomista Mat, can you decribe what you see? Why not try and make one yourself?
What is the best way to shunt these carriages so that each train can continue its journey?
Here are more buildings to picture in your mind's eye. Watch out - they become quite complicated!