I first bought this book when my granddaughter was 9, and my son said she read it over and over again from cover to cover, which was unusual for her. She'd also discuss information she found with him. This is now her 4th book and she looks forward to receiving it; I enjoy watching her become really excited when she opens this gift. She told me she was hoping I'd bought it for her. I told her that her dad had told me she enjoys the book, and she said she finds new information each time she reads it and her younger siblings enjoy the pictures as she reads the book to them.The pages are heavy-duty, and they're filled with bright pictures and a format that holds her interest as well as that of younger kids. There is also a 3D format with a free app she can download. She is a person who enjoys learning about new and different things, and she Googles for additional information on a subject she is particularly interested in. She even found a subject for one of her school papers!It's well worth its price - a format that's interesting even for kids who can't yet read, a source of unusual information all in one place, and a resource for school work and all family members all in one book!