Some people just learn math best through stories. Math stories can be a great, fun way to learn concepts before getting into specifics. A lot of Calculus books are really dry or go straight to the equations without building basic understanding first.
These calculus books introduce the main concepts through a short fairy tale and then get into all the math. The books help build conceptual understanding first, and then get into the details of problem solving.
I (the author) have been tutoring calculus for over ten years now, so I know which things about Calculus tend to be confusing. I tutor a lot of AP Calculus, so the content in this book is designed to cover what is covered in that class; this book is also part of a series, so it doesn’t cover all of AP Calc by itself, just the definition of a derivative.
The topics covered here build on each other and every little detail is covered (I’ve tried to make it ridiculously clear, since I can’t be there to answer your questions directly while you read- although you can email me if you get stuck somewhere!)
If you’re taking high school calculus or the first college calculus course, this book would be a great study supplement for you. It includes lots of practice problems with answers and worked examples.