Zone 21 - Fast Math Solitaire

Zone 21 - Fast Math Solitaire is a mathematical card game where players clear cards from the table while keeping their running total between 0 and 21, with bonuses for hitting 21. The game offers multiplayer features, including the ability to play against friends and competitors worldwide, with the chance to earn real-world rewards and cash prizes. Players can also compete in Skillz, a competition platform with leaderboards and challenges.