My book is utterly useless - it vaguely gives me a history behind it, its motivations, and then lists an example in which it precedes to write a bunch of utterly false statements and then just.. spits out the answer. Can someone explain to me what on Earth is going on in the attached picture? If this is not a notational confusion or typos in my book, then I must assert that Euclid's Algorithm makes absolutely no sense. 212 = 106.2, therefore here you go. I demand the author be sent to the lunatic asylum immediately.