No need to stop the puzzle fun with the big book of sudoku volume -I! Sharpen your mind and practice deductive reasoning with this second volume of sudoku puzzles for adults, including more than 540 challenges across four difficulty levels: warm-up, challenging, and tough. When you are done, test your skills on the ultimate samurai sudoku puzzle—5 puzzles linked together by one central puzzle! Can you become a master samurai? Challenge accepted! Over 500 puzzles & solutions: hours of fun and entertainment to enjoy. Variety of levels: from levels 1 to 3 increasing levels of difficulty, including beginner, medium, and hard. Lay flat: spiral-bound and paperback lays flat for ease of use at home or on the go. Makes a great gift: for the sudoku puzzle lover, these books make great gifts for any birthdays, stocking suffers, road trips, and more.