I just started subneting, I think I'm pretty good at it for the most part, using binary math I can figure it out rather quickly. But I just started reading Odom's method with the interesting octet/magic number. If anyone has his new book on 100-101, please tell me pg. 384/385 with fig. 14-8 is just fraught with errors on the subnet masks. It makes the entire explanation quite confusing until you actually see it done on his video.
I'm not sure if it would violate forum rules to upload a screenshot or quote verbatim from the book, but hopefully someone can confirm this.