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?
Ben and his mum are planting garlic. Use the interactivity to help you find out how many cloves of garlic they might have had.
Can you work out how to balance this equaliser? You can put more than one weight on a hook.
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?
Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?
Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.
Use the clues to colour each square.
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?
Can you put the numbers from 1 to 15 on the circles so that no consecutive numbers lie anywhere along a continuous straight line?
How many trains can you make which are the same length as Matt's and Katie's, using rods that are identical?
Can you cover the camel with these pieces?
Here are some rods that are different colours. How could I make a yellow rod using white and red rods?
An odd version of tic tac toe
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?
Hover your mouse over the counters to see which ones will be removed. Click to remove them. The winner is the last one to remove a counter. How you can make sure you win?
If you hang two weights on one side of this balance, in how many different ways can you hang three weights on the other side for it to be balanced?
Try to stop your opponent from being able to split the piles of counters into unequal numbers. Can you find a strategy?
How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?
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 interactivities to complete these Venn diagrams.
Place the numbers 1 to 6 in the circles so that each number is the difference between the two numbers just below it.
Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.
Try out the lottery that is played in a far-away land. What is the chance of winning?
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?
Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?
Use the interactivities to fill in these Carroll diagrams. How do you know where to place the numbers?
Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.
Can you put the numbers 1 to 8 into the circles so that the four calculations are correct?
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?
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. . . .
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?
A game for 1 person to play on screen. Practise your number bonds whilst improving your memory
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 2 people that everybody knows. You can play with a friend or online. If you play correctly you never lose!
An interactive activity for one to experiment with a tricky tessellation
If you have only four weights, where could you place them in order to balance this equaliser?
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 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.
A game for two people that can be played with pencils and paper. Combine your knowledge of coordinates with some strategic thinking.
A train building game for two players. Can you be the one to complete the train?
A game for 1 or 2 people. Use the interactive version, or play with friends. Try to round up as many counters as possible.
In your bank, you have three types of coins. The number of spots shows how much they are worth. Can you choose coins to exchange with the groups given to make the same total?
Can you spot the similarities between this game and other games you know? The aim is to choose 3 numbers that total 15.
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.
Use the interactivity or play this dice game yourself. How could you make it fair?
Terry and Ali are playing a game with three balls. Is it fair that Terry wins when the middle ball is red?
This is a game for two players. Can you find out how to be the first to get to 12 o'clock?