To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
My second grade students had an under-the-table-black-market wait list to read this book when I added it to my classroom library. The kids wanted to bring it to recess and lunch to finish it. You can't beat that.