Show that for any triangle it is always possible to construct 3 touching circles with centres at the vertices. Is it possible to construct touching circles centred at the vertices of any polygon?

To avoid losing think of another very well known game where the patterns of play are similar.

The aim of the game is to slide the green square from the top right hand corner to the bottom left hand corner in the least number of moves.

A metal puzzle which led to some mathematical questions.

Start with any number of counters in any number of piles. 2 players take it in turns to remove any number of counters from a single pile. The winner is the player to take the last counter.

A right-angled isosceles triangle is rotated about the centre point of a square. What can you say about the area of the part of the square covered by the triangle as it rotates?

Match the cards of the same value.

Can you beat the computer in the challenging strategy game?

This game challenges you to locate hidden triangles in The White Box by firing rays and observing where the rays exit the Box.

A group of interactive resources to support work on percentages Key Stage 4.

A simple spinner that is equally likely to land on Red or Black. Useful if tossing a coin, dropping it, and rummaging about on the floor have lost their appeal. Needs a modern browser; if IE then at. . . .

A collection of resources to support work on Factors and Multiples at Secondary level.

Help the bee to build a stack of blocks far enough to save his friend trapped in the tower.

There are 27 small cubes in a 3 x 3 x 3 cube, 54 faces being visible at any one time. Is it possible to reorganise these cubes so that by dipping the large cube into a pot of paint three times you. . . .

A tool for generating random integers.

The interactive diagram has two labelled points, A and B. It is designed to be used with the problem "Cushion Ball"

Discover a handy way to describe reorderings and solve our anagram in the process.

Place a red counter in the top left corner of a 4x4 array, which is covered by 14 other smaller counters, leaving a gap in the bottom right hand corner (HOME). What is the smallest number of moves. . . .

An environment that enables you to investigate tessellations of regular polygons

Match pairs of cards so that they have equivalent ratios.

The classic vector racing game brought to a screen near you.

Use Excel to investigate the effect of translations around a number grid.

Practise your skills of proportional reasoning with this interactive haemocytometer.

Can you give the coordinates of the vertices of the fifth point in the patterm on this 3D grid?

Use an interactive Excel spreadsheet to explore number in this exciting game!

This set of resources for teachers offers interactive environments to support work on loci at Key Stage 4.

An Excel spreadsheet with an investigation.

A java applet that takes you through the steps needed to solve a Diophantine equation of the form Px+Qy=1 using Euclid's algorithm.

An environment that simulates a protractor carrying a right- angled triangle of unit hypotenuse.

Use an Excel to investigate division. Explore the relationships between the process elements using an interactive spreadsheet.

Can you put the 25 coloured tiles into the 5 x 5 square so that no column, no row and no diagonal line have tiles of the same colour in them?

Use Excel to practise adding and subtracting fractions.

Use Excel to explore multiplication of fractions.

Use an Excel spreadsheet to explore long multiplication.

Here is a chance to play a fractions version of the classic Countdown Game.

A simple file for the Interactive whiteboard or PC screen, demonstrating equivalent fractions.

Use an interactive Excel spreadsheet to investigate factors and multiples.

A collection of our favourite pictorial problems, one for each day of Advent.

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?

We can show that (x + 1)² = x² + 2x + 1 by considering the area of an (x + 1) by (x + 1) square. Show in a similar way that (x + 2)² = x² + 4x + 4

This is an interactivity in which you have to sort the steps in the completion of the square into the correct order to prove the formula for the solutions of quadratic equations.

A counter is placed in the bottom right hand corner of a grid. You toss a coin and move the star according to the following rules: ... What is the probability that you end up in the top left-hand. . . .

On the 3D grid a strange (and deadly) animal is lurking. Using the tracking system can you locate this creature as quickly as possible?

Can you beat Piggy in this simple dice game? Can you figure out Piggy's strategy, and is there a better one?

Charlie likes tablecloths that use as many colours as possible, but insists that his tablecloths have some symmetry. Can you work out how many colours he needs for different tablecloth designs?

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.

in how many ways can you place the numbers 1, 2, 3 … 9 in the nine regions of the Olympic Emblem (5 overlapping circles) so that the amount in each ring is the same?

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