Help us caption and translate this video on Amara.org: http://www.amara.org/en/v/B2yL/ Esercizi: http://www.khanacademy.org/exercises?exid=addition_4 Traduzione in Italiano del video Addition 4 http://www.youtube.com/watch?v=fOXo4p4WDKM http://www.khanacademy.org/video/addition-4?playlist=Arithmetic Help us caption & translate this video! http://amara.org/v/B2yL/