Arithmetical 24 is a very simple game. You have 4 cards. The numbers on the cards are between 1 and 13. Click on any two cards to select them, then click +, -, x, or / to create a new card. The two used cards will be discarded. When there is only one card left and it is 24, you win.
Calculator 24 can auto solve Arithmetical 24, just enter 4 numbers, it will show you answers.