One Teacher’s Story

My name is Brian Coughlin, and I teach mathematics at Columbus Catholic High school—a school which recently (in the 2012-2013 school year) began its “1-to-1 iPad Initiative” (in which every student who didn’t already own an iPad would be loaned one by the school). As part of the initiative, the math department decided to investigate electronic textbooks instead of classic “paper” textbooks, for at least three reasons: for interactivity (eBooks usually have at least internet hyperlinks to tutorials, etc., and sometimes have interactive content), for cost (eBooks were usually $30 or less, while paper texts were $80 or more), and weight (some of our students were carrying 40-50 lbs. of books for their classes, and the 1000+ page math texts weren’t helping; the eBooks could all be stored on the 3-lb. iPad). I (as the advanced math teacher) was assigned to look for suitable electronic textbooks, and I searched through dozens of possibilities.

(I know that some of this next part will sound like a clichéd “blurb”, but honestly, this is how the story unfolded!)

I’d already know of a number of “free” Calculus textbooks which were available for download (usually in PDF format), but—to put the matter bluntly—they were usually worth what I paid for them, quality-wise (i.e. not very good, and completely unsuitable as texts; some were too abstruse, others were to simplistic, and still others didn’t seem to sequence their lessons in any coherent, logical progression at all). When I found the CK-12 series, however, I stopped dead in my tracks… since the Calculus book (which was the first CK-12 FlexBook I saw) was very good, and comparable to the paper text we’d been using. To my amazement, I then discovered that most of the other (free!) books in the CK-12 series (Trigonometry, etc.) were very suited to our needs, as well… and I ended up using three of them (Calculus, Math Analysis [in place of Precalculus—I supplemented it a bit], and Trigonometry) for this year’s courses.

There were, of course, some ups and downs (but heavens, the price is right!). Here’s my take on the books we used, thus far:

  • The Calculus FlexBook is excellent; my only criticisms would be that there are a few typos/mismatches in the exercises/answer keys at the end of the first two chapters, and that the number of exercises at the end of each section should (in my opinion, and in the opinion of several other teachers and professors I know) be far bigger—at least 50-75 problems (rather than the usual 10), with plenty of low-order problems which eventually lead up to the more complex, multi-step problems. In addition, there was the occasional “auto-numbering” error in the problem sets (e.g. someone seems to have used an auto-numbering program such as is found in MS Word, but it numbered every end-of-line, regardless of whether it was a new question or not! This yielded some mismatches in the problem sets and answers, including cases where there were “14 answers” to only “10 questions”! These got far fewer as the book went on, however.
  • The Math Analysis FlexBook was “shoehorned” into service as a Precalculus book, so some of my comments may not be quite fair; but the book misses several key concepts of a typical Precalculus class (e.g. Conics, and how to graph/analyze them), and the small number of exercises in each section seems to have forced the writers to “pack in” far too much material into each section, and the limited number of exercises has the same “drinking from a fire-hose” effect for the students. (See #1.) This book also suffered from the “auto-numbering” problems mentioned in #1. I may be looking for a replacement for this book, next year.
  • The Trigonometry Flexbook was the most difficult (and least satisfactory) to use, for two reasons: the “density and formatting problems” which were mentioned in #1 and #2 (above), and the fact that many needed pictures (JPEG’s, etc.) simply didn’t transfer to the PDF (or to the eBook version) at all! As such, many of the problems were rendered impossible (e.g. “use the following diagram to answer problems #1-8”, but the diagram was missing). However: when I looked about for a replacement, I found the “Trigonometry Concepts” Flexbook… and though the PDF version had some of the formatting errors of the previous version, the ePub version was wonderful! Not only were the formatting errors minimal, but the sections were so well-explained, so “piecemeal” (rather than trying to teach an entire chapter of material in one section), and so good in “drill and practice” exercises which the students needed, that we adopted it (and loved it) immediately! What a difference!

I want to make clear: I deliberately got my criticisms (in this story) out of the way first, so that I could end on several positive notes! The CK-12 Flexbooks are a God-send, and—even despite the issues with formatting, etc.—they measured up admirably to their paper counterparts. They managed to save our department at least $4000 in textbook costs, this year, they harmonize nicely with our iPad initiative (I especially like the hyperlinks to math tutorials at the end of each section, even in the PDF versions of the FlexBooks!), they are wonderfully portable; not only are they not 10-15-lb. paper books, but students can download the PDF versions of the FlexBooks to their laptop and desktop computers at home [I put copies of these on DropBox for them], and those students who chose to buy non-iPad tablets could still use and read the texts, unlike the iPad app-based books. The Calculus and Trigonometry Concepts FlexBooks cover all the needed material, and even the Math Analysis book (which I conscripted into service where it wasn’t quite designed to go) does its job well. And again: I can’t rave (positively) enough about the “Trigonometry Concepts” Flexbook!

If the books could be proofread (and who expected pristine editing, after only one year?), harmonized a bit more with the “standard/canonical” sequence of chapters/units usually used in high schools, spread out a bit so as to cover the material more discretely and slowly (rather than putting numerous lessons into one mega-lesson), augment the sections with plentiful exercises (of graduated difficulty and complexity, with plenty of drill-and-practice exercises in the beginning of each section’s exercises), and secure the formatting transfer (especially of graphic images), no one—including the “big name” publishers–would be able to TOUCH these books! Thank you so much for your tireless efforts, CK-12!


Brian Coughlin
Math Instructor
Columbus Catholic High School
Marshfield, WI