Exercise your mind with fun and addictive sudoku puzzles! These sudoku puzzles are easy to learn, tough to master, and impossible to put down! Includes  216 classic sudoku puzzles. - Small, stylish book fits perfectly in your bag without taking up too much space. - Spiral binding allows you to lay the book flat while you work. - Complete answer key is found at the back of the book. - 256 pages Publications International, Ltd. (​PIL)  publishes books and products for kids and adults in many categories: reference, leisure, inspirational, automotive, sports, cookbooks, stationery (New Seasons), interactive and early learning (Little Grasshopper Books).