Виконати додавання 2 способами43+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