I bought this with idea of giving it to a 5 year old. Upon arrival, it seemed much too advanced. You have 4 to 8 years. I checked the DK website and they indicated age 8+. The book is great and will go to an older child. This book is so well put together that an adult would benefit by having it for a reference.
So many questions were hard to answer when my 2 1/2 year old son started asking me (why do crickets make that noise? etc.) so, I bought this as a reference. Now, we read a section every night and he has so much knowledge from this book. It is very easy to read and has many detailed and colorful pictures (even boring subjects hold your interest!). My son, who is now 3 1/2 tells everyone how the noise is made by crickets rubbing their legs together. I've even learned a few things myself.