Place the numbers 1 to 6 in the circles so that each number is the difference between the two numbers just below it.
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?
Can you put the numbers 1 to 8 into the circles so that the four calculations are correct?
Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.
Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.
What do the numbers shaded in blue on this hundred square have in common? What do you notice about the pink numbers? How about the shaded numbers in the other squares?
Use the clues to colour each square.
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?
How many trains can you make which are the same length as Matt's and Katie's, using rods that are identical?
Here are some rods that are different colours. How could I make a yellow rod using white and red rods?
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?
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....?
What happens when you try and fit the triomino pieces into these two grids?
Use the interactivity to help get a feel for this problem and to find out all the possible ways the balls could land.
Try out the lottery that is played in a far-away land. What is the chance of winning?
Choose a symbol to put into the number sentence.
How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?
In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?
Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?
Can you put the numbers from 1 to 15 on the circles so that no consecutive numbers lie anywhere along a continuous straight line?
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.
There are three versions of this challenge. The idea is to change the colour of all the spots on the grid. Can you do it in fewer throws of the dice?
Find out how we can describe the "symmetries" of this triangle and investigate some combinations of rotating and flipping it.
An interactive game to be played on your own or with friends. Imagine you are having a party. Each person takes it in turns to stand behind the chair where they will get the most chocolate.
Can you find all the different triangles on these peg boards, and find their angles?
A game to be played against the computer, or in groups. Pick a 7-digit number. A random digit is generated. What must you subract to remove the digit from your number? the first to zero wins.
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?
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?
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. . . .
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?
Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.
Imagine a wheel with different markings painted on it at regular intervals. Can you predict the colour of the 18th mark? The 100th mark?
Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?
A game for 2 people that everybody knows. You can play with a friend or online. If you play correctly you never lose!
Cut four triangles from a square as shown in the picture. How many different shapes can you make by fitting the four triangles back together?
A train building game for two players. Can you be the one to complete the train?
Terry and Ali are playing a game with three balls. Is it fair that Terry wins when the middle ball is red?
A card pairing game involving knowledge of simple ratio.
Practise your tables skills and try to beat your previous best score in this interactive game.
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
Here is a chance to play a version of the classic Countdown Game.
Can you complete this jigsaw of the multiplication square?
Practise your number bonds whilst improving your memory in this matching pairs game.
Use your mouse to move the red and green parts of this disc. Can you make images which show the turnings described?
How many different triangles can you draw on the dotty grid which each have one dot in the middle?
Train game for an adult and child. Who will be the first to make the train?
Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.
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.