Memory Match (Super Mario 64 DS)
From the Super Mario Wiki
Memory Match is a minigame belonging to Luigi in Super Mario 64 DS, and also one of the Table minigames in New Super Mario Bros.. Betting three Coins, Luigi will serve a group of eight cards upside down, which the player must match them up with their twins. By completing a challenge succesfully, the player will gain a double amount of Coins bet and will also receive a Star as a point.
If the player matches different cards, a Coin will be given to Luigi from the bet amount, causing likely to lose a Star if Luigi takes all these Coins. Losing all the money to bet, the game will quit.
Memory Master is a harder version of this minigame, having sixteen cards to play. It is only found in Super Mario 64 DS.
In multiplayer, there are twenty cards. The person who goes first is chosen randomly. They go in order. If they match, two points and get to go again until they are wrong. Once all cards gone, most points wins.
 In-game instructions
Pick two matching cards to make them disappear. Clear all the cards to win.