Will Shortz Presents Ultra Easy Pocket Sudoku: 150 Fast, Fun Puzzles

Simply put: Sudoku is fun, mind-boggling, and relaxing—all at once. Says New York Times crossword editor and bestselling author Will Shortz: “The game can be played at any difficulty level, and it is surprisingly addictive. Soon you’ll see for yourself. Pick up a pencil. Can you do sudoku?”