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

Use the interactivity to create some steady rhythms. How could you create a rhythm which sounds the same forwards as it does backwards?

In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?

Imagine a wheel with different markings painted on it at regular intervals. Can you predict the colour of the 18th mark? The 100th mark?

Can you explain the strategy for winning this game with any target?

If you have only four weights, where could you place them in order to balance this equaliser?

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?

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!

Here is a chance to play a version of the classic Countdown Game.

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?

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

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.

Choose the size of your pegboard and the shapes you can make. Can you work out the strategies needed to block your opponent?

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.

Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?

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. . . .

An interactive activity for one to experiment with a tricky tessellation

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

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?

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?

An environment which simulates working with Cuisenaire rods.

Mr McGregor has a magic potting shed. Overnight, the number of plants in it doubles. He'd like to put the same number of plants in each of three gardens, planting one garden each day. Can he do it?

A game for 2 people that everybody knows. You can play with a friend or online. If you play correctly you never lose!

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?

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.

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

Train game for an adult and child. Who will be the first to make the train?

A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.

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.

Seeing Squares game for an adult and child. Can you come up with a way of always winning this game?

Can you put the numbers 1 to 8 into the circles so that the four calculations are correct?

A game in which players take it in turns to choose a number. Can you block your opponent?

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.

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

Can you complete this jigsaw of the multiplication square?

Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.

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

Here is a solitaire type environment for you to experiment with. Which targets can you reach?

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?

Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.

How have the numbers been placed in this Carroll diagram? Which labels would you put on each row and column?

Can you work out what is wrong with the cogs on a UK 2 pound coin?

Use the interactivity to investigate what kinds of triangles can be drawn on peg boards with different numbers of pegs.

Can you find all the different ways of lining up these Cuisenaire rods?