Calculation Solitaire is an interesting solitaire card game that deviates from a lot of other card games in terms of the way that it's played. Calculation has 5 piles and 4 foundations. Neither the foundations or the piles work in a way that is similar to most other solitaire card games. First of all, to put a card into the foundation you have to build up by multiples of the card to the right of the foundation. To make things easier I put the value of the card you need to place next to the right of the foundation. When placing a card in the foundation, you also don't have to worry about suit. The 5 piles are also a little weird. You can not move any cards between the two piles once you have moved a card into it. You also can place a card in any pile without regard to what card is currently at the top of the pile.