A Li'l More On That Wily Matt Parker....

I already wrote a blurb at MathTango about Matt Parker's fantastic book, "Things To Make and Do In the Fourth Dimension," but now that I've finished reading it, just want to add a few quick notes:

1)  First, I'll reiterate it's a wonderful volume -- I enjoyed the second half (which touched on several of my favorite topics, and also told perhaps the most fun story of Tartaglia's rivalry with Fior over algebraic/cubic equations) even more than the first half.
2)  Do note however, that at least parts of the volume may require slightly more math sophistication, or interest, or just persistence, than some of the other volumes I included on my Holiday gift list; i.e. while Matt's book is a fun and educational read, not every chapter is an easy read. 
3)  Also, one small complaint:  the book lacks an index, which because of the sheer number and diversity of topics/information included, would've been helpful.
4)  Finally, (and the REAL reason for this additional posting), BE SURE to read the "Acknowledgements" section at the very conclusion of the book! (...a section readers often skip over). Not only is the section entertaining to read, BUT in it are buried these innocuous, cryptic lines:

"Oh yeah, and there is a competition hidden somewhere in this book. If anyone wins it, I'll think of a suitable prize. Beware of the traps."

Leave it to Matt to concoct such a ploy! And I assume by "competition," he is not referencing proving the Riemann hypothesis! ;-).  (The book poses various questions and problems at points, but I'm not sure what is being referred to as "a competition" or "the traps" -- could be fun going back through the pages trying to figure out what it's all about.)
Anyway, have at it, and, with this heads-up, may one of my readers win the prize!