A ladder 3m long rests against a wall with one end a short distance from its base. Between the wall and the base of a ladder is a garden storage box 1m tall and 1m high. What is the maximum distance. . . .

Which exact dilution ratios can you make using only 2 dilutions?

Can you break down this conversion process into logical steps?

Match pairs of cards so that they have equivalent ratios.

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

Can you fill in the mixed up numbers in this dilution calculation?

Which dilutions can you make using 10ml pipettes and 100ml measuring cylinders?

Which dilutions can you make using only 10ml pipettes?

Meg and Mo need to hang their marbles so that they balance. Use the interactivity to experiment and find out what they need to do.

Meg and Mo still need to hang their marbles so that they balance, but this time the constraints are different. Use the interactivity to experiment and find out what they need to do.

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

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

Mo has left, but Meg is still experimenting. Use the interactivity to help you find out how she can alter her pouch of marbles and still keep the two pouches balanced.

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

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?

Use Excel to explore multiplication of fractions.

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.

A red square and a blue square overlap so that the corner of the red square rests on the centre of the blue square. Show that, whatever the orientation of the red square, it covers a quarter of the. . . .

Use the computer to model an epidemic. Try out public health policies to control the spread of the epidemic, to minimise the number of sick days and deaths.

These formulae are often quoted, but rarely proved. In this article, we derive the formulae for the volumes of a square-based pyramid and a cone, using relatively simple mathematical concepts.

Prove Pythagoras' Theorem using enlargements and scale factors.

Can you find a way to turn a rectangle into a square?

Use your skill and knowledge to place various scientific lengths in order of size. Can you judge the length of objects with sizes ranging from 1 Angstrom to 1 million km with no wrong attempts?

Two engines, at opposite ends of a single track railway line, set off towards one another just as a fly, sitting on the front of one of the engines, sets off flying along the railway line...

Experiment with the interactivity of "rolling" regular polygons, and explore how the different positions of the red dot affects the distance it travels at each stage.

Experiment with the interactivity of "rolling" regular polygons, and explore how the different positions of the red dot affects its speed at each stage.

It is possible to identify a particular card out of a pack of 15 with the use of some mathematical reasoning. What is this reasoning and can it be applied to other numbers of cards?

Can you set the logic gates so that the number of bulbs which are on is the same as the number of switches which are on?

Experiment with the interactivity of "rolling" regular polygons, and explore how the different positions of the red dot affects its vertical and horizontal movement at each stage.

Explore displacement/time and velocity/time graphs with this mouse motion sensor.

An Excel spreadsheet with an investigation.

Use Excel to practise adding and subtracting fractions.

Use an interactive Excel spreadsheet to investigate factors and multiples.

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

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.

Practise your skills of proportional reasoning with this interactive haemocytometer.

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

Triangle ABC has equilateral triangles drawn on its edges. Points P, Q and R are the centres of the equilateral triangles. What can you prove about the triangle PQR?

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

Use an Excel spreadsheet to explore long multiplication.

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

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

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

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

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

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. . . .

First Connect Three game for an adult and child. Use the dice numbers and either addition or subtraction to get three numbers in a straight line.

Can you explain the strategy for winning this game with any target?