Найдите сумму:
а) 23 + 47 + 11 + 29;
б) 18 + 15 + 32 + 45;
в) 27 + 36 + 28 + 23 + 14;
г) 276 + 118 + 324;
д) 127 + 32 + 93 + 308;
е) 15 + 45 + 65 + 35 + 40.
23 + 47 + 11 + 29 = (23 + 47) + (11 + 29) = 70 + 40 = 110
18 + 15 + 32 + 45 = (18 + 32) + (15 + 45) = 50 + 60 = 110
27 + 36 + 28 + 23 + 14 = (27 + 23) + (36 + 14) + 28 = 50 + 50 + 28 = 100 + 28 = 128
276 + 118 + 324 = (276 + 324) + 118 = 600 + 118 = 718
127 + 32 + 93 + 308 = (127 + 93) + (32 + 308) = 220 + 340 = 560
15 + 45 + 65 + 35 + 40 = (15 + 35) + (45 + 65) + 40 = 50 + 110 + 40 = 160 + 40 = 200