I think that this book is interesting, and makes you want to keep reading it to see what happens next.
It's about a fifth grade class that has boys and girls in it. The boys and girls are having a contest, because the boys think the girls talk too much, and the girls think the boys talk too much. So, what they do is not talk for a whole week, and whichever team talks less, wins.
I also think this book would be good for around age 8.