Medium and hard Sudoku for those who love solving fun and challenging puzzles. Sudoku Puzzle Book Ideally, this large print book is suitable for teens to adults. Everyone in the family will enjoy this Sudoku brain game. Research shows that Sudoku can help improve concentration. Sudoku makes you think and helps with critical thinking. Sudoku is a memory game and is a great way to improve your memory and keep it sharp. This Sudoku game can be very relaxing. Take your time and enjoy a quiet day. This is a great gift for Birthdays and Christmas. Solutions are in the back Puzzles are printed only on the fronts of the pages for easier to handle book and no worries of bleed through when working on another puzzle on the back of the page Large print 8.5" x 11 " 50 puzzles from medium to hard With matte-finish for an elegant look for a professional look and feel.