Zotz! vs Crystal Math

Zotz! is an enjoyable time-waster, a form of perceptual practice, good for training the brain and the eyes; there is no timer and no score, no pressure, just a simple challenge waiting for you whenever you like. The game supposes a deck of cards, where each card has four attributes, and each attribute on any given card has one of three possible values: Number (one, two, or three), Color (red, blue, or green), Fill (solid, hazy, or empty), and Shape (diamond, oval, or rectangle). All you have to do is to spot, amongst the visible cards, any three cards which, for each attribute, are either all identical or all different. Colors, middle fill type, and number of cards in the layout can all be customized. Full instructions, with examples, are included.

Crystal Math brings brain training to a whole new level. No matter if against the clock, or against other math cracks, improve your mental arithmetic on a daily basis, unlock all achievements one by one and become the new math champion. Test you math skills in four challenging modes. Daily Challenge: Solve a new challenge every day and fight for a spot on the highscore list in three difficulties. Step up your game though, you only get one try! Duel: Challenge other players to a duel, or accept someone's challenge and fight for the winnig time. Time Attack: Practice under competition conditions. You have 30 seconds to solve the challenge. Free Game: Explore the game free of pressure and find your personal techniques for upcoming challenges. Choose an avatar and show math cracks around the globe what you are capable of. What are you waiting for? Pick up your slide rule and get started!