I'm an early intervention teacher and this book is one of the favorites for my kids. Trains tend to be pretty popular for this age, so there is interest from the start. I like how it brings in concepts such as color, speed ("fast!"), location (in/out) and even disappearance (gone! At the end) into the book. The pictures are bright and engaging and my kids usually won't stand for a single look through... Its at least two to three times at least!