New variant
Four foundations each build to a King by a different interval — by ones, twos, threes, and fours — regardless of suit. Draw one card at a time from the stock and place it on any of the four waste piles, or directly onto a foundation if it fits. The top card of any waste pile may always be moved to a legal foundation. Careful planning of your waste piles is the key to winning.
Click the stock to draw a card, then click a waste pile or foundation to place it.
Calculation Solitaire is a non-standard patience game where suits are completely irrelevant and the four foundations build by arithmetic intervals rather than consecutive ranks. The four foundations start on Ace, 2, 3, and 4, and build by increments of 1, 2, 3, and 4 respectively — wrapping around when they exceed 13. This means foundation placement is calculated, not obvious, and waste-pile management is the primary tactical challenge.
One Ace, one 2, one 3, and one 4 are removed from the deck and placed on the four foundation starting positions. The foundations build as follows:
Suits are irrelevant. Four waste piles serve as temporary storage. The stock deals one card at a time; a card goes to a foundation if it fits, or to any one of the four waste piles. Only the top waste card is available. Win when all 52 cards reach foundations.
The four waste piles sound like generous storage, but they are the game’s central trap. A card placed in a waste pile stays there until all cards above it are removed — and removal only happens by playing them to foundations. A waste pile that accumulates many cards in the wrong order becomes a prison: the needed card is buried under cards that will not be foundationed until later in the sequence.
Strong Calculation play involves thinking about the sequence each waste pile will need to deliver. Ideally, waste pile 1 holds cards needed for foundation A, waste pile 2 for foundation B, and so on — though maintaining this alignment is rarely perfect.
Knowing the full sequence of each foundation in advance is the primary cognitive skill in Calculation. With four different intervals, a card of rank 7 might be immediately needed on foundation A (if at 6), several steps away on foundation B (if at 8), or on a different foundation entirely. Memorizing or quickly computing each foundation’s next required rank before each stock deal prevents misplacing cards.
The last card on every foundation is always a King — all four sequences end at 13. This is the game’s one guarantee of symmetry in an otherwise purely arithmetic structure.