The game uses a 3x3 square board. 2 players take turns to play, either placing a red on an empty square, or changing a red to orange, or orange to green. The player who forms 3 of 1 colour in a line wins.
Some puzzles requiring no knowledge of knot theory, just a careful inspection of the patterns. A glimpse of the classification of knots and a little about prime knots, crossing numbers and knot arithmetic.
Investigations based on an Indian game.
16 cards face down. Alternatively you can choose the number of cards you want to play with.
The object of the game is to match pairs of numbers and number sentences, like pelmanism or pelmathism.
You play the game on the computer, but not against the computer. It is a game of skill, concentration and knowing your number bonds with an added element of chance. Good number hunting and Good Luck!
Where does the maths come in? The numbers on the card are either a single number or a short number sentence such as 5+3. You have to match two cards that have the same total. Are some number bonds easier to remember than others? Find out which number bonds you need to get to know better.
To download a printable version of this game use the links below. If you print double-sided, the cards will each have an NRICH logo on the back. If you would prefer them to be blank on the back, please just print the first page.