виконати додавання 2способами43+38 27+27 66+35 18+23 49+35

43+38 = (40+30) + (3+8) = 70 + 11 = 81,           = 43 + 30 + 8 = 73 + 8 = 81,27+27 = (20+20) + (7+7) = 40 + 14 = 54,           = 27 + 20 + 7 = 47 + 7 = 54,66+35 = (60+30) + (6+5) = 90 + 11 = 101,           = 66 + 30 + 5 = 96 + 5 = 101,18+23 = (10+20) + (8+3) = 30 + 11 = 41,           = 18 + 20 + 3 = 38 + 3 = 41,49+35 = (40+30) + (9+5) = 70 + 14 = 84,           = 49 + 30 + 5 = 79 + 5 = 84