Can you make a 3x3 cube with these shapes made from small cubes?
What is the best way to shunt these carriages so that each train can continue its journey?
Swap the stars with the moons, using only knights' moves (as on a chess board). What is the smallest number of moves possible?
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?
Building up a simple Celtic knot. Try the interactivity or download the cards or have a go on squared paper.
Hover your mouse over the counters to see which ones will be removed. Click to remover them. The winner is the last one to remove a counter. How you can make sure you win?
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?
This article for teachers describes how modelling number properties involving multiplication using an array of objects not only allows children to represent their thinking with concrete materials,. . . .
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?
Design an arrangement of display boards in the school hall which fits the requirements of different people.
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 how many cubes were used to make this open box? What size of open box could you make if you had 112 cubes?
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 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. . . .
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?
Paint a stripe on a cardboard roll. Can you predict what will happen when it is rolled across a sheet of paper?
What is the total area of the four outside triangles which are outlined in red in this arrangement of squares inside each other?
This practical problem challenges you to make quadrilaterals with a loop of string. You'll need some friends to help!
Make a cube out of straws and have a go at this practical challenge.
Can you find ways of joining cubes together so that 28 faces are visible?
Can you fit the tangram pieces into the outline of these rabbits?
Can you fit the tangram pieces into the outline of this plaque design?
Can you fit the tangram pieces into the outline of the telescope and microscope?
What is the greatest number of squares you can make by overlapping three squares?
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
Looking at the picture of this Jomista Mat, can you decribe what you see? Why not try and make one yourself?
How many different ways can you find of fitting five hexagons together? How will you know you have found all the ways?
How many different cuboids can you make when you use four CDs or DVDs? How about using five, then six?
How can you paint the faces of these eight cubes so they can be put together to make a 2 x 2 cube that is green all over AND a 2 x 2 cube that is yellow all over?
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?
Can you cut up a square in the way shown and make the pieces into a triangle?
In each of the pictures the invitation is for you to: Count what you see. Identify how you think the pattern would continue.
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?
Try this interactive strategy game for 2
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 outline of Wai Ping, Wah Ming and Chi Wing?
Make a flower design using the same shape made out of different sizes of paper.
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 fit the tangram pieces into the outline of Little Ming?
Can you fit the tangram pieces into the outlines of these clocks?
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?
Can you fit the tangram pieces into the outline of this shape. How would you describe it?
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?
This article for teachers describes a project which explores thepower of storytelling to convey concepts and ideas to children.
This problem invites you to build 3D shapes using two different triangles. Can you make the shapes from the pictures?
Imagine a wheel with different markings painted on it at regular intervals. Can you predict the colour of the 18th mark? The 100th mark?
What shape is made when you fold using this crease pattern? Can you make a ring design?
Where can you put the mirror across the square so that you can still "see" the whole square? How many different positions are possible?