(5,4-2 целых 1/3) разделить на 7цел. 2/3
(5,4 - 2 1/3) / 7 2/3 = (54/10 - 7/3) / 7 2/3 = (162/30 - 70/30) / 23/3 = 92/30 / 23/3 = 2/5 = 0,4