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.
The book is engaging and have fun stuff to attracts the young readers. But some of the facts are basically wrong or far from accuracy. The cost of 1g of Saffron is completely off compared to gold or some mis-information about penicillin ... there are just a few we found out in the first 50 pages or so. The authors or publisher need someone to fact check !