Решебник по математике 4 класс Моро Часть 1, 2 Часть 1 Задание 27

\[\boxed{\text{27\ (27).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

Пояснение.

Решение.

\[1.\ 27\ :3 = 9.\]

\[2.\ 45 + 9 = 54.\]

\[3.\ 54 - 12 = 42.\ \]

\[1.\ 36\ :3 = 12.\]

\[2.\ 12 \cdot 2 = 24.\]

\[3.\ 90 - 24 = 66.\ \]

\[1.\ 84\ :4 = (80 + 4)\ :4 =\]

\[= 20 + 1 = 21.\]

\[2.\ 21 \cdot 3 = (20 + 1) \cdot 3 =\]

\[= 60 + 3 = 63.\]

\[3.\ 63 + 2 = 65.\ \]

\[1.\ 10 \cdot 9 = 90.\]

\[2.\ 100 - 90 = 10.\]

\[3.\ 10 - 8 = 2.\ \]

\[1.\ 15 \cdot 3 = (10 + 5) \cdot 3 =\]

\[= 30 + 15 = 45.\]

\[2.\ 45 \cdot 0 = 0.\]

\[3.\ 17 + 0 = 17.\ \]

\[1.\ 5 \cdot 5 = 25.\]

\[2.\ 75\ :5 = (50 + 25)\ :5 =\]

\[= 10 + 5 = 15.\]

\[3.\ 25 + 15 = 40.\ \]

\[1.\ 17 \cdot 3 = (10 + 7) \cdot 3 =\]

\[= 30 + 21 = 51.\]

\[2.\ 2 \cdot 10 = 20.\]

\[3.\ 51 + 20 = 71.\ \]

\[1.\ 5 \cdot 2 = 10.\]

\[2.\ 10\ :10 = 1.\]

\[3.\ 80 - 1 = 79.\ \]

\[1.\ 72\ :6 = (60 + 12)\ :6 =\]

\[= 10 + 2 = 12.\]

\[2.\ 6 \cdot 5 = 30.\]

\[3.\ 12 + 30 = 42.\]

\[2.\ \]

\[1.\ 45 + 27 = 72.\]

\[2.\ 72\ :3 = (60 + 12)\ :3 =\]

\[= 20 + 4 = 24.\]

\[3.\ 24 - 12 = 12.\ \]

\[1.\ 90 - 36 = 90 - 30 - 6 =\]

\[= 60 - 6 = 54.\]

\[2.\ 54\ :3 = (30 + 24)\ :3 =\]

\[= 10 + 8 = 18.\]

\[3.\ 18 \cdot 2 = (10 + 8) \cdot 2 =\]

\[= 20 + 16 = 36.\ \]

\[1.\ 3 + 2 = 5.\]

\[2.\ 84\ :4 = (80 + 4)\ :4 =\]

\[= 20 + 1 = 21.\]

\[3.\ 21 \cdot 5 = (20 + 1) \cdot 5 =\]

\[= 100 + 5 = 105.\ \]

\[1.\ 9 - 8 = 1.\]

\[2.\ 10 \cdot 1 = 10.\]

\[3.\ 100 - 10 = 90.\ \]

\[1.\ 17 + 15 = 32.\]

\[2.\ 32 \cdot 3 = (30 + 2) \cdot 3 =\]

\[= 90 + 6 = 96.\]

\[3.\ 96 \cdot 0 = 0.\ \]

\[1.\ 75\ :5 = (50 + 25)\ :5 =\]

\[= 10 + 5 = 15.\]

\[2.\ 5 \cdot 5 = 25.\]

\[3.\ 25 + 15 = 40.\ \]

\[1.\ 3 + 2 = 5.\]

\[2.\ 17 \cdot 5 = (10 + 7) \cdot 5 =\]

\[= 50 + 35 = 85.\]

\[3.\ 85 \cdot 10 = 850.\ \]

\[1.\ 80 - 5 = 75.\]

\[2.\ 75 \cdot 2 = (70 + 5) \cdot 2 =\]

\[= 140 + 10 = 150.\]

\[3.\ 150\ :10 = 15.\ \]

\[2.\ 72\ :6 = (60 + 12)\ :6 =\]

\[= 10 + 2 = 12.\]

\[1.\ 6 \cdot 5 = 30.\]

\[3.\ 12 + 30 = 42.\ \]