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