Whether you are new to sudoku or craving a fresh challenge, this sudoku book will give your brain a healthy workout. This puzzle-packed sudoku collection features: Hundreds of sudoku puzzles. 5 levels of difficulty - from beginner to mind-benders. Sudoku grids that are large, easy to read, and fill out. An answer key for those puzzles that leave you stumped. Spiral-binding for ease of use. 192 pages. Part of the popular Brain Games series, designed to help keep your brain cognitively fit, flexible, and young. Boost your concentration, logic, and reasoning and lower your brain age in minutes a day!