I answered 7th/8th grade, but as others have observed, it's hard to generalize.
We have a 13 year old daughter who has just finished 7th grade. She's a
voracious reader. I let her borrow my K1 a couple of times to read school assignments when we couldn't find the p-book at the library or the bookstore, or when it was something that I wanted to read too. To digress for a minute--
A Confederacy of Dunces is on her reading list for the summer. I was going to get it for my Kindle, but it's not available.
Don't know why, but it surprises me when that happens.
I was kinda hoping she'd get hooked on e-books so that I could give her my K1 and I could graduate to something else (not sure what--K2? 505?). But very much to my surprise, she didn't really seem to like reading on the Kindle. So I'm still stuck with it
