C., K. and I started playing this game in Paris using a deck of cards and trying o use addition, subtraction, multiplication and division to make 4 cards come to 24. Jack, Queen, King are treated as 10.

Here are the official rules

http://www.pagat.com/adders/24.html

These are some of the samples:

(6-4+1) * 8 = 24

(10 * 3) – (10 – 4) = 24

This is similar to 24 Game but public domain and using a standard deck of playing cards. The cards are shuffled and divided equally between four players. The cards become each player’s draw deck. Every player simultaneously flip open their top card. Then they try to reach “24” using (+,-,*,/) with the four open cards. J,Q,K count as ten. If any player thinks they have got it, they slam their hand on the table. One can also slam the table to bluff other players into thinking they have the solution. After three players have slammed their hands, the remaining player must choose one of the three players to give the solution. If the chosen player answers correctly, the remaining player takes the four cards and put them at the bottom of his draw deck. If the chosen player has no solution or answers wrongly, he/she must take the four cards and put them at the bottom of his/her draw deck. Game ends when one player exhausts his/her draw deck. If no player can think up a solution (some card combinations cannot form 24), they can all agree to put back their respective cards, reshuffle, and draw a new card from their draw deck. Game ends when one player exhausts his/her draw deck.