Why are textbooks are large when we only use a small section of them?

Let’s say it’s 9th grade, you’ve got a 9th grade specific textbook that’s 1000 pages; But in your 9th grade class you only use maybe 30 pages max. What about the rest of the book? Why are there so many topics for that one grade, and that one class, but you only discuss maybe 5 topics in the whole book?

Submitted January 01, 2019 at 03:09PM by bibbble http://bit.ly/2Sv1kuL