Choose a difficulty then press start. The game will progress through various levels, each corresponding to a particular multiple (perfect squares or primes are also on the harder levels), and you need to sort each of 8 tiles, shown in turn, according to whether or not they satisfy the condition for the level. (Sorting is by dragging the tile into either the Yes or No area.)

Five points are scored for each correct tile, and if they are all sorted correctly before the bonus has ticked down to 0, the remaining bonus points are added to the score. The game ends if time runs out or three errors are made on a particular level, or if all levels are completed.

An excellent score at the Easy level is anything over 500. On the Difficult level you should aim for 750, and if you can score more than 1000 on Extreme difficulty, you really are an expert at multiples!

Use the Review buttons below to see all the sorting decisions made during the current game.