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.

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?

When number pyramids have a sequence on the bottom layer, some interesting patterns emerge...

How good are you at finding the formula for a number pattern ?

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

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.

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

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

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.

Try entering different sets of numbers in the number pyramids. How does the total at the top change?

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

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

Match the cards of the same value.

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

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

This resource contains a range of problems and interactivities on the theme of coordinates in two and three dimensions.

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

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?

Use Excel to explore multiplication of fractions.

If you continue the pattern, can you predict what each of the following areas will be? Try to explain your prediction.

Can you make a right-angled triangle on this peg-board by joining up three points round the edge?

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

Can you find a reliable strategy for choosing coordinates that will locate the robber in the minimum number of guesses?

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

Euler discussed whether or not it was possible to stroll around Koenigsberg crossing each of its seven bridges exactly once. Experiment with different numbers of islands and bridges.

Players take it in turns to choose a dot on the grid. The winner is the first to have four dots that can be joined to form a square.

Work out how to light up the single light. What's the rule?

An Excel spreadsheet with an investigation.

This resource contains interactive problems to support work on number sequences at Key Stage 4.

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

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

Six balls of various colours are randomly shaken into a trianglular arrangement. What is the probability of having at least one red in the corner?

Use Excel to practise adding and subtracting fractions.

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.

Use an interactive Excel spreadsheet to investigate factors and multiples.

Use an Excel spreadsheet to explore long multiplication.

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

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

Slide the pieces to move Khun Phaen past all the guards into the position on the right from which he can escape to freedom.

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.

A game for 2 players that can be played online. Players take it in turns to select a word from the 9 words given. The aim is to select all the occurrences of the same letter.

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. . . .

Prove Pythagoras' Theorem using enlargements and scale factors.

A game for 2 players. Can be played online. One player has 1 red counter, the other has 4 blue. The red counter needs to reach the other side, and the blue needs to trap the red.

The opposite vertices of a square have coordinates (a,b) and (c,d). What are the coordinates of the other vertices?

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

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 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?

Can you spot the similarities between this game and other games you know? The aim is to choose 3 numbers that total 15.