Use the interactivity to help get a feel for this problem and to find out all the possible ways the balls could land.
Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.
How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?
Place the numbers 1 to 6 in the circles so that each number is the difference between the two numbers just below it.
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?
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?
Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?
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....?
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 are some rods that are different colours. How could I make a yellow rod using white and red rods?
How many trains can you make which are the same length as Matt's and Katie's, using rods that are identical?
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?
How many different triangles can you draw on the dotty grid which each have one dot in the middle?
Can you put the numbers from 1 to 15 on the circles so that no consecutive numbers lie anywhere along a continuous straight line?
Use the clues to colour each square.
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?
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.
Choose the size of your pegboard and the shapes you can make. Can you work out the strategies needed to block your opponent?
Board Block game for two. Can you stop your partner from being able to make a shape on the board?
Seeing Squares game for an adult and child. Can you come up with a way of always winning this game?
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?
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.
Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.
Imagine a wheel with different markings painted on it at regular intervals. Can you predict the colour of the 18th mark? The 100th mark?
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.
What shaped overlaps can you make with two circles which are the same size? What shapes are 'left over'? What shapes can you make when the circles are different sizes?
In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?
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.
Use the interactivity to investigate what kinds of triangles can be drawn on peg boards with different numbers of pegs.
Terry and Ali are playing a game with three balls. Is it fair that Terry wins when the middle ball is red?
Take it in turns to make a triangle on the pegboard. Can you block your opponent?
A game for 1 or 2 people. Use the interactive version, or play with friends. Try to round up as many counters as possible.
Can you find all the different triangles on these peg boards, and find their angles?
How many different triangles can you make on a circular pegboard that has nine pegs?
Can you put the numbers 1 to 8 into the circles so that the four calculations are correct?
Sort the houses in my street into different groups. Can you do it in any other ways?
Use your mouse to move the red and green parts of this disc. Can you make images which show the turnings described?
Use the interactivity to find out how many quarter turns the man must rotate through to look like each of the pictures.
Choose a symbol to put into the number sentence.
Use the Cuisenaire rods environment to investigate ratio. Can you find pairs of rods in the ratio 3:2?
A train building game for two players. Can you be the one to complete the train?
Explore this interactivity and see if you can work out what it does. Could you use it to estimate the area of a shape?
What is the greatest number of squares you can make by overlapping three squares?
These interactive dominoes can be dragged around the screen.
Watch this film carefully. Can you find a general rule for explaining when the dot will be this same distance from the horizontal axis?
Here is a chance to play a version of the classic Countdown Game.
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
Choose 13 spots on the grid. Can you work out the scoring system? What is the maximum possible score?
This is a game for two players. Can you find out how to be the first to get to 12 o'clock?