\[\boxed{\mathbf{Страница}\mathbf{\ \ 77}\mathbf{.}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[\boxed{\mathbf{26}\mathbf{.}\mathbf{\ }}\]
\[9 \cdot 9 = 81\]
\[56\ :7 = 8\]
\[2 \cdot 8 = 16\]
\[8 \cdot 8 = 64\]
\[72\ :8 = 9\]
\[6 \cdot 5 = 30\]
\[24\ :4 = 6\]
\[7 \cdot 3 = 21\]
\[18\ :3 = 6\]
\[\boxed{\mathbf{27}\mathbf{.}\mathbf{\ }}\]
\[Первый\ способ.\]
\[Второй\ способ.\]
\[\boxed{\mathbf{28}\mathbf{.}\mathbf{\ }}\]