Customer Reviews, including Product Star Ratings, help customers to learn more about the product and decide whether it is the right product for them.
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.
I bought this for my friend who has been the Finance Director at Woolworths, Blockbuster Video, General Motors and Lehman Brothers, he cant understand why he keeps messing up...I do....it works.
Reviewed in the United Kingdom on 21 November 2012
Just received this. It's actually a Christmas present but I thought I'd have a play with it. Quite good but if you use the square root button the answer is always RIGHT!