Ebook: Mathematics for 3D Game Programming & Computer Graphics (Game Development Series)

If you're trying to find examples of 3D vector operations (dot and cross products, especially) that keep the interest of a mixed class of 18-25 year olds, this book is a fantastic source. If you're approaching the topic from the point of view of a programmer, trying to acquire the necessary math, it may be a bit dense. I'm sure many of the examples are now out-of-date, compared to current 3D implementations, but I learned quite a bit, anyway.