Canasta
Canasta is a card game usually played by two teams of two players, with two decks of cards.
Players start with 11 cards each. None of the other players knows what cards you hold, even your partner!
Then the fun begins. Each team aims to pick up extra cards and lay down matching cards, called melds.
It requires skill, mental agility and, at the end of the game, mental arithmetic skills are tested in working out the score.
It is fun, a lot less complicated to play than to explain, and rather addictive!