The computer starts with all the lights off, but then clicks 3, 4 or 5 times at random, leaving some lights on. Can you switch them off again?

Advent Calendar 2010 - a mathematical game for every day during the run-up to Christmas.

Everthing you have always wanted to do with dominoes! Some of these games are good for practising your mental calculation skills, and some are good for your reasoning skills.

A game for 2 players. Take turns to place a counter so that it occupies one of the lowest possible positions in the grid. The first player to complete a line of 4 wins.

A Sudoku with clues given as sums of entries.

An ordinary set of dominoes can be laid out as a 7 by 4 magic rectangle in which all the spots in all the columns add to 24, while those in the rows add to 42. Try it! Now try the magic square...

A game for two people, who take turns to move the counters. The player to remove the last counter from the board wins.

A game for 2 people. Take turns joining two dots, until your opponent is unable to move.

A game for 2 players. Can be played online. One player has 1 red counter, the other has 4 blue. The red counter needs to reach the other side, and the blue needs to trap the red.

This article for teachers describes several games, found on the site, all of which have a related structure that can be used to develop the skills of strategic planning.

Solve this Sudoku puzzle whose clues are in the form of sums of the numbers which should appear in diagonal opposite cells.

A game for 2 players. Given a board of dots in a grid pattern, players take turns drawing a line by connecting 2 adjacent dots. Your goal is to complete more squares than your opponent.

In this game you throw two dice and find their total, then move the appropriate counter to the right. Which counter reaches the purple box first? Is this what you would expect?

Help the bee to build a stack of blocks far enough to save his friend trapped in the tower.

Interactive game. Set your own level of challenge, practise your table skills and beat your previous best score.

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

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.

The aim of the game is to slide the green square from the top right hand corner to the bottom left hand corner in the least number of moves.

In this matching game, you have to decide how long different events take.

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

Nim-7 game for an adult and child. Who will be the one to take the last counter?

In this game for two players, you throw two dice and find the product. How many shapes can you draw on the grid which have that area or perimeter?

Try this matching game which will help you recognise different ways of saying the same time interval.

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

Can you spot the similarities between this game and other games you know? The aim is to choose 3 numbers that total 15.

Can you make the birds from the egg tangram?

Here is a version of the game 'Happy Families' for you to make and play.

An article for teachers and pupils that encourages you to look at the mathematical properties of similar games.

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.

Can you work out how to win this game of Nim? Does it matter if you go first or second?

An extension of noughts and crosses in which the grid is enlarged and the length of the winning line can to altered to 3, 4 or 5.

A game for 1 person to play on screen. Practise your number bonds whilst improving your memory

Can you beat Piggy in this simple dice game? Can you figure out Piggy's strategy, and is there a better one?

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.

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?

Use your addition and subtraction skills, combined with some strategic thinking, to beat your partner at this game.

In this article for teachers, Liz Woodham describes the criteria she uses to choose mathematical games for the classroom and shares some examples from NRICH.

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?

We think this 3x3 version of the game is often harder than the 5x5 version. Do you agree? If so, why do you think that might be?

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

Use the tangram pieces to make our pictures, or to design some of your own!

A game for 2 players. Using 2 dice, some counters and a games board, can you form a line of counters from one side of the board to the other?

A game for 2 people. Take turns placing a counter on the star. You win when you have completed a line of 3 in your colour.