Help us caption and translate this video on Amara.org: http://www.amara.org/en/v/B2x1/ Esercizi:http://www.khanacademy.org/exercises?exid=subtracting_fractions Traduzione in Italiano del video Adding and subtracting fractions http://www.youtube.com/watch?v=52ZlXsFJULI http://www.khanacademy.org/video/adding-and-subtracting-fractions?playlist=Pre-algebra