As a math major I found this book to be relatively interesting. The number "e" is an important part of mathematics. I was very curious about how this book was going to be written. How can you write 200 or so pages about a single number? Not even a single concept. A single number known as "e".
As the book progressed it made sense. They started by talking about the discovery of logarithmic functions. This lead to them trying to find the "natural log" (which we now know has a base of e). IN chapter 3, the number e is discovered by using compound interest which uses the formula (1+1/n)^n. In this formula n stand for the amount of time. As n goes to infinity, the formula approaches 2.7182.... which we now know as "e". When mathematicians realized this phenomena, they discovered limits, which then allowed them to discover calculus. It then goes on to discuss what calculus and the number "e" allowed us to discover after that.
As a mathematician is it is amazes me that one number could be written into one book. While I did find the book interesting, there were many parts that were very dry. There were a lot of calculations derivations that were very confusing to me. I enjoyed the history and the discoveries, but the pure math was way over my head.
If you are extremely interested in math, I would recommend this book as it talks about some of the most important features and topics of mathematics. If you have curiosity about how e, logarithmic function, and calculus came about, I would recommend this book. If you don't have a background in math at all, then you would hate this book. It probably would make little to no sense you. If you do have a background in math but approach math by saying "just give me the formula" then this book is not for you. You would not care about how any of these concepts cam to be.
In the end I would give this book a 3.5 out of 5. It was interesting to learn about the concepts in more detail and to learn how they were discovered. The only problem was that the pure math derivations were way too complicated for me.