How many times in twelve hours do the hands of a clock form a right angle? Use the interactivity to check your answers.

A metal puzzle which led to some mathematical questions.

Use the interactivity to move Mr Pearson and his dog. Can you move him so that the graph shows a curve?

Use the interactivity to investigate what kinds of triangles can be drawn on peg boards with different numbers of 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.

Can you create a story that would describe the movement of the man shown on these graphs? Use the interactivity to try out our ideas.

Watch this film carefully. Can you find a general rule for explaining when the dot will be this same distance from the horizontal axis?

What shaped overlaps can you make with two circles which are the same size? What shapes are 'left over'? What shapes can you make when the circles are different sizes?

A game for two or more players that uses a knowledge of measuring tools. Spin the spinner and identify which jobs can be done with the measuring tool shown.

It's easy to work out the areas of most squares that we meet, but what if they were tilted?

Can you find all the different ways of lining up these Cuisenaire rods?

Can you work out what is wrong with the cogs on a UK 2 pound coin?

Use the interactivity or play this dice game yourself. How could you make it fair?

Use the interactivity to create some steady rhythms. How could you create a rhythm which sounds the same forwards as it does backwards?

Investigate how the four L-shapes fit together to make an enlarged L-shape. You could explore this idea with other shapes too.

A shape and space game for 2,3 or 4 players. Be the last person to be able to place a pentomino piece on the playing board. Play with card, or on the computer.

Explore the different tunes you can make with these five gourds. What are the similarities and differences between the two tunes you are given?

What are the areas of these triangles? What do you notice? Can you generalise to other "families" of triangles?

Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?

Overlaying pentominoes can produce some effective patterns. Why not use LOGO to try out some of the ideas suggested here?

Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.

Semi-regular tessellations combine two or more different regular polygons to fill the plane. Can you find all the semi-regular tessellations?

Use the interactivities to complete these Venn diagrams.

An interactive game for 1 person. You are given a rectangle with 50 squares on it. Roll the dice to get a percentage between 2 and 100. How many squares is this? Keep going until you get 100. . . .

Can you fit the tangram pieces into the outline of Granma T?

Explore this interactivity and see if you can work out what it does. Could you use it to estimate the area of a shape?

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!

Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?

A circle rolls around the outside edge of a square so that its circumference always touches the edge of the square. Can you describe the locus of the centre of the circle?

Find out how we can describe the "symmetries" of this triangle and investigate some combinations of rotating and flipping it.

Do you know how to find the area of a triangle? You can count the squares. What happens if we turn the triangle on end? Press the button and see. Try counting the number of units in the triangle now. . . .

A game to be played against the computer, or in groups. Pick a 7-digit number. A random digit is generated. What must you subract to remove the digit from your number? the first to zero wins.

A game for 2 people that can be played on line or with pens and paper. Combine your knowledege of coordinates with your skills of strategic thinking.

A tetromino is made up of four squares joined edge to edge. Can this tetromino, together with 15 copies of itself, be used to cover an eight by eight chessboard?

You can move the 4 pieces of the jigsaw and fit them into both outlines. Explain what has happened to the missing one unit of area.

What are the coordinates of the coloured dots that mark out the tangram? Try changing the position of the origin. What happens to the coordinates now?

Start by putting one million (1 000 000) into the display of your calculator. Can you reduce this to 7 using just the 7 key and add, subtract, multiply, divide and equals as many times as you like?

A game for 1 person. Can you work out how the dice must be rolled from the start position to the finish? Play on line.

An interactive activity for one to experiment with a tricky tessellation

Exchange the positions of the two sets of counters in the least possible number of moves

A game for 2 people that everybody knows. You can play with a friend or online. If you play correctly you never lose!

You have 27 small cubes, 3 each of nine colours. Use the small cubes to make a 3 by 3 by 3 cube so that each face of the bigger cube contains one of every colour.

Work out the fractions to match the cards with the same amount of money.

How many different triangles can you make on a circular pegboard that has nine pegs?

Can you find all the different triangles on these peg boards, and find their angles?

What is the greatest number of squares you can make by overlapping three squares?