\[Страница\ 54.\]
\[\boxed{\mathbf{8.}}\]
\[8 \cdot 4 = 32\]
\[32\ :8 = 4\]
\[32\ :4 = 8\]
\[9 \cdot 3 = 27\]
\[27\ :3 = 9\]
\[27\ :9 = 3\]
\[7 \cdot 5 = 35\]
\[35\ :5 = 7\]
\[35\ :7 = 5\]
\[\boxed{\mathbf{9.}}\]
\[1)\ 8 \cdot 2 = 16\]
\[2)\ 8\ :2 = 4\]
\[3)\ 8 - 2 = 6\]
\[\boxed{\mathbf{10.}}\]
\[35 - 17 = 18\ (лампочек) - в\ \]
\[другой\ витрине.\]
\[Ответ:18\ лампочек.\]