Amazon calculates a product’s star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers, and factors that establish reviewer trustworthiness.
My youngest (7 yrs.) really enjoys "The Last Firehawk" series of books. I purchased the first in the series some months back and he recently asked me to get the rest. I ordered #2-4 and he sat down and read them all, one after the other on a rainy afternoon.
My 5yo son loves this series. As soon as we get one of these books we sit down and read it cover to cover without delay! Great quest adventure story, action, teamwork, tactics, friendship and perservering through adversity.