Can you work out how to balance this equaliser? You can put more than one weight on a hook.

Use the information about Sally and her brother to find out how many children there are in the Brown family.

Here are some rods that are different colours. How could I make a dark green rod using yellow and white rods?

Can you hang weights in the right place to make the equaliser balance?

Can you use the numbers on the dice to reach your end of the number line before your partner beats you?

Choose four of the numbers from 1 to 9 to put in the squares so that the differences between joined squares are odd.

Complete the squares - but be warned some are trickier than they look!

This was a problem for our birthday website. Can you use four of these pieces to form a square? How about making a square with all five pieces?

Sort the houses in my street into different groups. Can you do it in any other ways?

Can you complete this jigsaw of the multiplication square?

Ben and his mum are planting garlic. Use the interactivity to help you find out how many cloves of garlic they might have had.

The idea of this game is to add or subtract the two numbers on the dice and cover the result on the grid, trying to get a line of three. Are there some numbers that are good to aim for?

Use the number weights to find different ways of balancing the equaliser.

Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.

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?

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?

If there are 3 squares in the ring, can you place three different numbers in them so that their differences are odd? Try with different numbers of squares around the ring. What do you notice?

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?

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?

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?

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

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....?

If you can post the triangle with either the blue or yellow colour face up, how many ways can it be posted altogether?

Yasmin and Zach have some bears to share. Which numbers of bears can they share so that there are none left over?

How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?

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?

A game for 1 or 2 people. Use the interactive version, or play with friends. Try to round up as many counters as possible.

Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.

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!

Exchange the positions of the two sets of counters in the least possible number of moves

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?

Can you put the 25 coloured tiles into the 5 x 5 square so that no column, no row and no diagonal line have tiles of the same colour in them?

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?

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 activity for one to experiment with a tricky tessellation

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.

Hover your mouse over the counters to see which ones will be removed. Click to remover them. The winner is the last one to remove a counter. How you can make sure you win?

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.

Work out the fractions to match the cards with the same amount of money.

How many different rhythms can you make by putting two drums on the wheel?

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 2 people that can be played on line or with pens and paper. Combine your knowledege of coordinates with your skills of strategic thinking.

Three beads are threaded on a circular wire and are coloured either red or blue. Can you find all four different combinations?