For two people the game requires two, or more, sets of BusyBusy Elbe cards ~ or any suitable cards with the numbers zero through to nine. One set limits the scope, three or more sets increase the length of the game and involve slightly more skill.
Three, or more, players will require further sets of cards. I suggest one set per player as a guide for starting. Modify accordingly as things progress.
Lay the cards ~ face up ~ in a random arrangement on the table top.
Announce the rules for the game, and maybe even display them for all to see. There are numerous variations. I start with the simplest ~ thus ~
When no further pairs are possible the game ends. The person with the greatest number of cards is declared the winner.
The rules can change for each game ~ depending on the needs of the students. The person in charge will need to be quick-witted in order to set things up between games quickly and sensibly. Prior prepation helps, but would involve a great many cards.
Laying down the cards on a slightly softer surface ~ such as traditional green baize felt material ~ makes picking the cards easier. It allows the finger nails to get under the card.
'Best of five games' might be a useful guide to keeping the interest going before boredom sets in.
Some disciplines need to be introduced if the game is to be played unsupervised. Taking turns is a great help if players are mismatched in any way. Laying the cards face down, and then sharing the task of turning them all over before starting cuts down the advantage for the ultra quick spotter or grabber. If etiquette and sportsmaship cannot be observed then refereeing ~ or a change of subject ~ will be required.
A tournament ladder can be introduced.