- This is a great way to teach children how to have fun with numbers at a young age, instead of growing up intimidated by them! This book is designed to be a great way to start kids ages 8-12 on Sudoku, but it is good for beginners of all ages. It should provide enough difficulty as the book progresses to keep even older kids challenged and amused.Have fun, and always remember: once you look at the solution, you can never unsee it!