Exercice 6:
712 =
700 + 10 + 2
400 + 40 + 2 =
442
578 =
500 + 10 + 1 =
333 =
300 + 70 + 7 =
193 =
400 + 20 + 8 =
681 =
500 + 80 + 8 =
