I started tutoring IGCSE Mathematics. In preparation for just a 1 hour class for 1 student, I noticed at least 3 mistakes (confirmed with their replies to me) in Chapter 21 of the Haese 0607 book (quadratic equations and functions). I even noticed a mistake in the errata (last updated almost 2 years ago though I found the 3 mistakes in just 1 day) for a different chapter (probability).
Dumb question: How are these mistakes going to be disseminated?
I mean if I've noticed these mistakes, I wonder about all the other readers on Earth (students, teachers, tutors, parents, etc) who notice mistakes. I think it would be tiresome for both the authors to reply to the same mistakes and the readers to type up emails instead of having some dynamic errata (forum i guess).