Bad Teacher (2011), Directed by Jake Kasdan – good movies with Cameron Diaz, Jason Segel, Justin Timberlake, Lucy Punch

A lazy, incompetent middle school teacher who hates her job, her students, and her co-workers is forced to return to teaching to make enough money for breast implants after her wealthy fiancé dumps her.

http://www.imdb.com/title/tt1284575