I bought this book for my 7yr old son, to introduce him to musical theory from a young age in the hope that it will help to improve his piano playing. He absolutely loves this book and even asks to do extra pages, which is amazing when normally the idea of extra homework sends him running! It really is helping him as an accompaniment to his piano lessons and we'll be keen to buy the next book when he's ready for it. His piano teacher has also been impressed with the book so far.
As a self taught pianist, who couldn't read music but decided to give it a go with my son, i've really found this book helpful and have learnt so much. I never imagined i'd be able to pick up musical theory but these books, really make it fun and interesting with little quizzes and puzzles to help you on your way.