Book Riot's Read Harder Challenge discussion

Has anyone read Wonder by RJ Palacio? I’m confused as to whether this is YA- my local library does not have it filed as such but a couple of reviews have referred to it as a YA book.

It's about a kid who is supposed to be in 5th grade...so more like a upper elementary/middle school book? I read it and enjoyed it, but it's definitely meant for a younger audience.

I've used it as a read aloud for kids in grades 6, 7 and 8. I think it is fine as a YA choice.

I have kids reading it in my Freshmen class as a 'relaxed read' but I generally classify it as a middle reader