Calculation Solitaire is a card game developed by AlgoTech for Android devices. This solitaire game is designed to be a brain-teaser, where cards are moved to the foundation by multiples of a number associated with each foundation pile. The game consists of four foundation piles, each ending up with a King in the following order: A, 2, 3, 4, 5, 6, 7, 8, 9, 10, J, Q, K.

The game starts with four foundation piles, each corresponding to its multiple. The remaining cards form the stock pile, and there is one waste pile that can only hold one card. The game also features four tableau piles that can be built up in any order, with only the top card available for play. The game is a test of skill, and a skilled player can win 80% of the time. The game's features include a clean interface, the ability to save the game state to play later, unlimited undo, and game play statistics.