57. Вычисли удобным способом:

  52 : 4 = (40 + 12) : 4 = 10 + 3 = 13

  90 : 6 = (60 + 30) : 6 = 10 + 5 = 15

  75 : 3 = (60 + 15) : 3 = 20 + 5 = 25

  100 : 4 = (80 + 20) : 4 = 20 + 5 = 25

  70 : 5 = (50 + 20) : 5 = 10 + 4 = 14

  63 : 9 · 13 = 7 · (10 + 3) = 70 + 21 = 91

  24 : 6 · 18 = 4 · (10 + 8) = 40 + 32 = 72

  72 : 9 · 12 = 8 · (10 + 2) = 80 + 16 = 96

  56 : 8 · 11 = 7 · 11 = 77

  45 : 9 · 14 = 5 · (10 + 4) = 50 + 20 = 70