|"E-Z Calculus", which was previously published under the titles "Calculus the Easy Way" and "Calculus by Discovery", aims to teach the fundamentals of calculus through the adventures of a man who has washed ashore in the mystic land of Carmorra. It seems that the people there are always faced with difficult mathematical problems that they discuss and solve by independently inventing the notions of differential and integral calculus, and our "hero" always seems to be able to guide them to an answer. In this way, the reader can feel a part of discovering calculus rather than just reading about it in its final form. Plus, the inclusion of kings and giants could also serve to make this "novel" more engrossing than your average calculus textbook. I can only barely bring myself to call this a "novel" however. In fact, it is neither a novel nor a collection of short stories but instead is really a textbook (even including end of section exercises) that uses the fictional setting of Carmorra much as another textbook might mention a farmer building a fence or a plane flying over a radar station. IMHO although there is a common fictional setting that runs throughout the textbook, this is not really a work of fiction in the usual sense of that word as it lacks an overall plot and character development.
(There are other books in the series like "E-Z Algebra" and "E-Z Statistics", all of which seem to take place in Carmorra.)
I am grateful to Hauke Reddmann for for rediscovering this book for me. In fact, I found it myself back in 1996 before I was interested in mathematically-flavored fiction. I ran across it in a university library and gave some thought to whether it would be useful as an educational tool. Then, a few years later when I started compiling this list, I had already forgotten the title and author and was unable to locate it until Hauke sent me a link to a posting about it this afternoon. Thanks, Hauke!