Частина 1 — Відповіді: Стр.25 (4)

4. Знайди значення виразів зручним для тебе способом.

73 – 46 = 73 – 50 + 4 = 23 + 4 = 27

69 + 18 = 70 + 18 – 1 = 88 – 1 = 87

52 – 16 = 52 – 20 + 4 = 32 + 4 = 36

26 + 38 = 26 + 40 – 2 = 66 – 2 = 64

57 + 35 = 60 + 35 – 3 = 95 – 3 = 92

100 – 94 = (90 – 90) + (10 – 4) = 6

18 + 18 = 20 + 18 – 2 = 38 – 2 = 36

42 – 35 = (30 + 12) – (30 + 5) = 7

80 – 16 = (70 – 10) + (10 – 6) = 60 + 4 = 64

28 + 28 = (20 + 20) + (8 + 8) = 40 + 16 = 56

91 – 74 = 91 – 70 = 21 – 4 = 17

51 + 19 = (50 + 10) + (1 + 9) = 60 + 10 = 70

46 + 34 = (40 + 30) + (6 + 4) = 70 + 10 = 80

85 – 58 = 85 – 50 = 35 – 8 = 27

56 + 2 = 58

90 – 62 = 90 – 60 = 30 – 2 = 28