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?
Here is a chance to play a version of the classic Countdown Game.
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.
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?
Can you explain the strategy for winning this game with any target?
Try entering different sets of numbers in the number pyramids. How does the total at the top change?
Starting with the number 180, take away 9 again and again, joining up the dots as you go. Watch out - don't join all the dots!
Can you find all the different triangles on these peg boards, and find their angles?
There are nine teddies in Teddy Town - three red, three blue and three yellow. There are also nine houses, three of each colour. Can you put them on the map of Teddy Town according to the rules?
Choose the size of your pegboard and the shapes you can make. Can you work out the strategies needed to block your opponent?
Choose a symbol to put into the number sentence.
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?
Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.
Can you make a cycle of pairs that add to make a square number using all the numbers in the box below, once and once only?
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
A and B are two interlocking cogwheels having p teeth and q teeth respectively. One tooth on B is painted red. Find the values of p and q for which the red tooth on B contacts every gap on the. . . .
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 have 4 red and 5 blue counters. How many ways can they be placed on a 3 by 3 grid so that all the rows columns and diagonals have an even number of red counters?
Can you make a right-angled triangle on this peg-board by joining up three points round the edge?
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.
Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.
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.
Choose 13 spots on the grid. Can you work out the scoring system? What is the maximum possible score?
A card pairing game involving knowledge of simple ratio.
Try out the lottery that is played in a far-away land. What is the chance of winning?
Practise your diamond mining skills and your x,y coordination in this homage to Pacman.
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?
This problem is based on a code using two different prime numbers less than 10. You'll need to multiply them together and shift the alphabet forwards by the result. Can you decipher the code?
Learn how to use the Shuffles interactivity by running through these tutorial demonstrations.
Place the numbers from 1 to 9 in the squares below so that the difference between joined squares is odd. How many different ways can you do this?
A tilted square is a square with no horizontal sides. Can you devise a general instruction for the construction of a square when you are given just one of its sides?
How many different triangles can you make on a circular pegboard that has nine pegs?
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. . . .
A train building game for 2 players.
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?
Work out the fractions to match the cards with the same amount of money.
Is it possible to place 2 counters on the 3 by 3 grid so that there is an even number of counters in every row and every column? How about if you have 3 counters or 4 counters or....?
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...
If you have only four weights, where could you place them in order to balance this equaliser?
Find out what a "fault-free" rectangle is and try to make some of your own.
Ahmed has some wooden planks to use for three sides of a rabbit run against the shed. What quadrilaterals would he be able to make with the planks of different lengths?
How have the numbers been placed in this Carroll diagram? Which labels would you put on each row and column?
Is this a fair game? How many ways are there of creating a fair game by adding odd and even numbers?
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.
Can you find all the different ways of lining up these Cuisenaire rods?
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?
An animation that helps you understand the game of Nim.
When number pyramids have a sequence on the bottom layer, some interesting patterns emerge...
Triangular numbers can be represented by a triangular array of squares. What do you notice about the sum of identical triangle numbers?