A classic collection of 500 hard Sudoku! Ideal for your commute, to challenge yourself at home, and for addicts of this brain bashing game, both kids and adults. This book with hours of fun inside makes a great gift! We've had your entertainment and convenience in mind when designing this book and thought about the small details which make a difference: Wide center margins making it easier to work on the puzzles when you fold the book Bigger font and better quality paper than newspapers and magazines - easy to read and write on without worry of bleed-through Problem levels has been expertly assessed for consistency. No wasted puzzle in this book. 4 problems per page with solutions at the end of the book