Use the interactivities to fill in these Carroll diagrams. How do you know where to place the numbers?

Investigate which numbers make these lights come on. What is the smallest number you can find that lights up all the lights?

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?

Can you complete this jigsaw of the multiplication square?

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

This article gives you a few ideas for understanding the Got It! game and how you might find a winning strategy.

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.

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....?

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

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.

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

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. . . .

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

These interactive dominoes can be dragged around the screen.

Practise your tables skills and try to beat your previous best score in this interactive game.

A train building game for two players. Can you be the one to complete the train?

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

Choose 13 spots on the grid. Can you work out the scoring system? What is the maximum possible score?

Can you put the numbers from 1 to 15 on the circles so that no consecutive numbers lie anywhere along a continuous straight line?

This is a game for two players. Can you find out how to be the first to get to 12 o'clock?

Practise your number bonds whilst improving your memory in this matching pairs game.

Watch this film carefully. Can you find a general rule for explaining when the dot will be this same distance from the horizontal axis?

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

Stop the Clock game for an adult and child. How can you make sure you always win this game?

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

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

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.

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

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.

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.

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

An interactive activity for one to experiment with a tricky tessellation

This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?

Arrange any number of counters from these 18 on the grid to make a rectangle. What numbers of counters make rectangles? How many different rectangles can you make with each number of counters?

The 2012 primary advent calendar features twenty-four of our posters, one for each day in the run-up to Christmas.

Ahmed has some wooden planks to use for three sides of a rabbit run against the shed. What quadrilaterals would he be able to make with the planks of different lengths?

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

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?

Use the interactivity or play this dice game yourself. How could you make it fair?

How many trains can you make which are the same length as Matt's and Katie's, using rods that are identical?

Each light in this interactivity turns on according to a rule. What happens when you enter different numbers? Can you find the smallest number that lights up all four lights?

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.