As mentioned in the syllabus, the book for our course is an OER (Open Education Resource) that is available to read online for free or for purchase for minimal cost from Amazon. This course is divided into 10 modules. The text for modules 2-9 come from chapters 2-9 of Math in Society by David Lippman. You can access these chapters in these ways:

You can download each chapter on the corresponding learning resources pages.
You can download a copy of chapters 2 - 9 all together in one file. This version is helpful if you want to load the book onto an e-reader (Kindle, iPad, etc.).
If you prefer to purchase a bound, printed copy of Math in Society, you can do so from Createspace or via Amazon for $15+shipping. Be aware the book may take about 10 days to arrive.

The text for module 1 is from a different OER, CK-12 Trigonometry by Lori Jordan and Mara Landers. The text for module 10 is from CK-12 Probability and Statistics - Advanced by Ellen Lawsky and Larry Ottman.

These chapters are hyperlinked on the learning resources pages in their respective modules.
You can also download a copy of module 1 reading and module 10 reading.