In August 2009, the MAA published the article The House That Calculus Built (James Stewart and the House That Calculus Built – Mathematical …) regarding the amazing manse that James Stewart constructed using the fortune earned from his excellent calculus texts. When I read the article, I experienced a mix of feelings, but mostly I felt like the article was mistitled: The House that Calculus Students Paid For.

There are, of course, good reasons that Stewart has made (and continues to make) so much money from his texts. They’re very well done. The writing is crisp; the problems interesting; and there are few to no errors. He also has multiple versions with different styles and perspectives (and, of course, the requisite multiple editions of each). It makes sense that a large number of college faculty have elected to use his books.

But for me, this level of profit margin called into question the value of the text. I also easily imagine how much more profit the publisher, Brooks-Cole, of Stewart’s texts has gained from this work. And it all feels disproportionate. Calculus is well-understood as a body of knowledge; its place in the college mathematics curriculum is generally agreed upon by the professional community; and calculus is, in my opinion, the intellectual property of humankind.

Reading the article again and thinking about the surrounding issues inspired me to undertake a project I’d had in the back of my mind for some time: to write my own calculus text. But there would be several major differences. First, it would have to be free to students, or free except for the cost of printing. Second, it would be open-source for other instructors, so that they could edit, modify, or rearrange if they desired. And finally, it would be designed to be read by students in a way that pushed them to be active learners.

While being free and open source are obvious differences from most texts, I hope it is the latter features that end up really distinguishing it. Many texts seem to have the ethos “watch me (your expert author) do a bunch of examples, and then you do a bunch of similar problems.” In the modern era with computing technologies such as Wolfram Alpha able to solve almost every routine calculus problem, I don’t think this textbook style serves our students well. So, I set out to write a text that would push students to apprehend the big ideas of calculus, often through activities where they themselves develop connections among key concepts, and that would push them to solve harder, more complicated, more open-ended problems than those found in most calculus texts. Readers should decide for themselves if these goals are being achieved in the text.

This all is very much a work in progress. While a draft of the differential calculus portion of the text is available, the integral calculus chapters are still being written. I’m grateful to a handful of people who are using the text and activities this fall, appreciate

their incoming feedback, and look forward to a revised and strengthened version being ready for Fall 2013. You can learn more about the project at http://opencalculus.wordpress.com/, and download the .pdf of the differential calculus text at http://opencalculus.wordpress.com/2012/08/09/initial-public-offering-differential-calculus/. Comments, questions, and other feedback can be shared directly with me at boelkinm at gvsu dot edu.