This manual of slide rule history and usage, as well as a detailed guide to its functions, includes typical use, problems, and settings. (Facsimile reprint edition of a book originally published in 1930.)
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 analyzes reviews to verify trustworthiness.