(Устно.) Выполни действия, используя приемы перестановки слагаемых.
16 + 47 + 34
28 + 58 + 72
85 + 77 + 15
31 + 27 + 19
62 + 75 + 38
53 + 84 + 47
45 + 69 + 31 + 55
46 + 31 + 24 + 49
62 + 43 + 28 + 27
16 + 47 + 34 = (16 + 34) + 47 = 50 + 47 = 97
28 + 58 + 72 = (28 + 72) + 58 = 100 + 58 = 158
85 + 77 + 15 = (85 + 15) + 77 = 100 + 77 = 177
31 + 27 + 19 = (31 + 19) + 27 = 50 + 27 = 77
62 + 75 + 38 = (62 + 38) + 75 = 100 + 75 = 175
53 + 84 + 47 = (53 + 47) + 84 = 100 + 84 = 184
45 + 69 + 31 + 55 = (45 + 55) + (69 + 31) = 100 + 100 = 200
46 + 31 + 24 + 49 = (46 + 24) + (31 + 49) = 70 + 80 = 150
62 + 43 + 28 + 27 = (62 + 28) + (43 + 27) = 90 + 70 = 160