Trust the 5 star rating this book has received by everyone! I have spent hours researching infant-toddler books in an attempt to foster my 16 mo. old's love of books. After spending major $$ and countless hours shopping for books, I have to say: This is absolutely one of the best interactive books we've ordered. It covers the concepts of numbers, letters, shapes, and opposites. The last page asks the reader to help Elmo search for a missing bear in his playroom. Children can look inside the piano, under an easel, etc. etc. to find it. Though some reviewers have noted that their young babies adore this book, I think it's more appropriate for the over 1 year old crowd. For one thing, it is super large board book. Young babies can't carry or manuever through the pages or flaps well. Secondly, while it's great to provide a numbers/letters introduction to babies, they will have a hard time focusing on the pages (they're very busy) and won't get much out of this book. In fact, while some younger infants (if they can open the flaps) will delight in looking under the number 10 to see the 10 bugs or lifting cookie monster's "full" bucket to see it "empty", they can't quite grasp these concepts yet. So, over all, this is a must-have to own for your 1 year-old and up. You can even purchase it early and then pull it out of the closet periodically to see if your kiddo is ready. Hope this helps. I'm off to search for more books by Anna Ross/Joe Mathieu.