11 Birthdays by Wendy Mass is a book about friendships. Amanda and Leo are truly the best of friends celebrating every birthday together until the turn 11. This is because during their tenth birthday Amanda over hears some boys telling Leo how uncool it is to have his party with a girl every year. The she doesn't talk to him until their 11th birthday when strange things start happening where they will need each other to figure it out. Ava D., Grade 6