Sudoku for Kids: Fun Number Puzzles for Ages 6 and Up The gradual approach to Sudoku presented in this book is designed to take any child or adult from complete beginner to confident problem solver. We start out with the simplest level. These puzzles are 4 boxes by 4 boxes and have most of the numbers filled in. As your skill level continues to improve, the puzzles get more and more difficult. We graduate to puzzles that...