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?
A group activity using visualisation of squares and triangles.
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 work out what shape is made by folding in this way? Why not create some patterns using this shape but in different sizes?
Cut four triangles from a square as shown in the picture. How many different shapes can you make by fitting the four triangles back together?
Draw three straight lines to separate these shapes into four groups - each group must contain one of each shape.
What shape is made when you fold using this crease pattern? Can you make a ring design?
How many different triangles can you make on a circular pegboard that has nine pegs?
What shape is the overlap when you slide one of these shapes half way across another? Can you picture it in your head? Use the interactivity to check your visualisation.
What is the total area of the four outside triangles which are outlined in red in this arrangement of squares inside each other?
Can you visualise what shape this piece of paper will make when it is folded?
Can you fit the tangram pieces into the silhouette of the junk?
Investigate how the four L-shapes fit together to make an enlarged L-shape. You could explore this idea with other shapes too.
Can you fit the tangram pieces into the outline of Granma T?
This challenge involves eight three-cube models made from interlocking cubes. Investigate different ways of putting the models together then compare your constructions.
How will you go about finding all the jigsaw pieces that have one peg and one hole?
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?
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 ...
Looking at the picture of this Jomista Mat, can you decribe what you see? Why not try and make one yourself?
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?
Can you fit the tangram pieces into the outlines of the workmen?
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 fit the tangram pieces into the outline of Mai Ling?
Can you fit the tangram pieces into the outline of Little Ming and Little Fung dancing?
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. . . .
What is the greatest number of squares you can make by overlapping three squares?
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 watering can and man in a boat?
Can you fit the tangram pieces into the outlines of Mai Ling and Chi Wing?
Can you cut up a square in the way shown and make the pieces into a triangle?
Can you cut a regular hexagon into two pieces to make a parallelogram? Try cutting it into three pieces to make a rhombus!
Can you fit the tangram pieces into the outline of Little Ming?
Have a go at this 3D extension to the Pebbles problem.
Can you fit the tangram pieces into the outline of this shape. How would you describe it?
ABCDEFGH is a 3 by 3 by 3 cube. Point P is 1/3 along AB (that is AP : PB = 1 : 2), point Q is 1/3 along GH and point R is 1/3 along ED. What is the area of the triangle PQR?
Can you fit the tangram pieces into the outlines of the chairs?
Can you fit the tangram pieces into the outlines of the lobster, yacht and cyclist?
Can you fit the tangram pieces into the outline of the child walking home from school?
Can you find ways of joining cubes together so that 28 faces are visible?
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?
How can the same pieces of the tangram make this bowl before and after it was chipped? Use the interactivity to try and work out what is going on!
How many different ways can you find of fitting five hexagons together? How will you know you have found all the ways?
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?
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?
Can you fit the tangram pieces into the outlines of these clocks?
Can you fit the tangram pieces into the outlines of these people?
Building up a simple Celtic knot. Try the interactivity or download the cards or have a go on squared paper.
Paint a stripe on a cardboard roll. Can you predict what will happen when it is rolled across a sheet of paper?
These are pictures of the sea defences at New Brighton. Can you work out what a basic shape might be in both images of the sea wall and work out a way they might fit together?
Use the lines on this figure to show how the square can be divided into 2 halves, 3 thirds, 6 sixths and 9 ninths.