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?

7 balls are shaken in a container. You win if the two blue balls touch. What is the probability of winning?

Identical discs are flipped in the air. You win if all of the faces show the same colour. Can you calculate the probability of winning with n discs?

This interactivity invites you to make conjectures and explore probabilities of outcomes related to two independent events.

Is this a fair game? How many ways are there of creating a fair game by adding odd and even numbers?

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

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. . . .

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

Imagine picking up a bow and some arrows and attempting to hit the target a few times. Can you work out the settings for the sight that give you the best chance of gaining a high score?

Try out the lottery that is played in a far-away land. What is the chance of winning?

Interactive game. Set your own level of challenge, practise your table skills and beat your previous best score.

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.

Use this animation to experiment with lotteries. Choose how many balls to match, how many are in the carousel, and how many draws to make at once.

Practise your diamond mining skills and your x,y coordination in this homage to Pacman.

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

Can you locate the lost giraffe? Input coordinates to help you search and find the giraffe in the fewest guesses.

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.

What is the relationship between the angle at the centre and the angles at the circumference, for angles which stand on the same arc? Can you prove it?

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

Learn how to use the Shuffles interactivity by running through these tutorial demonstrations.

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

Draw some isosceles triangles with an area of $9$cm$^2$ and a vertex at (20,20). If all the vertices must have whole number coordinates, how many is it possible to draw?

A tool for generating random integers.

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

Find the frequency distribution for ordinary English, and use it to help you crack the code.

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

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

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.

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...

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.

Can you find a relationship between the number of dots on the circle and the number of steps that will ensure that all points are hit?

A game for 1 person to play on screen. Practise your number bonds whilst improving your memory

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

Carry out some time trials and gather some data to help you decide on the best training regime for your rowing crew.

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.

Can you find triangles on a 9-point circle? Can you work out their angles?

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.

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.

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

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

Triangle numbers can be represented by a triangular array of squares. What do you notice about the sum of identical triangle numbers?

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

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

Can you fit the tangram pieces into the outline of this telephone?

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. . . .

This problem is about investigating whether it is possible to start at one vertex of a platonic solid and visit every other vertex once only returning to the vertex you started at.

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.