Somma di Numeri Misti con Denominatore Non Comune

Help us caption and translate this video on Amara.org: http://www.amara.org/en/v/B2uM/ Esercizi: http://www.khanacademy.org/exercise/adding_subtracting_mixed_numbers_1 Traduzione in Italiano del video Adding Mixed Numbers with Unlike Denominators http://www.youtube.com/watch?feature=player_embedded&v=CfBYGFm5gPA http://www.khanacademy.org/math/arithmetic/fractions/v/adding-mixed-numbers-with-unlike-denominators