\[\boxed{\mathbf{Проверочная\ работа\ №2.\ Нахождение\ части\ целого}}\]
\[\boxed{\mathbf{1.}}\]
\[5 \cdot 0,2 = 1.\]
\[\boxed{\mathbf{2.}}\]
\[300 \cdot 0,3 = 90.\]
\[\boxed{\mathbf{3.}}\]
\[63\ :9 = 7.\]
\[\boxed{\mathbf{4.}}\]
\[400\ :4 \cdot 3 = 300.\]
\[\boxed{\mathbf{5.}}\]
\[800\ :8 \cdot 3 = 300\ кг.\]
\[\mathbf{Нет.}\]
\[\boxed{\mathbf{6.}}\]
\[60\ :12 \cdot 5 = 25\ мин.\]
\[Да.\]
\[\boxed{\mathbf{7.}}\]
\[\mathbf{Да.}\]
\[\boxed{\mathbf{8.}}\]
\[x \cdot \frac{2}{7} = \frac{1}{2}\]
\[x = \frac{1}{2}\ :\frac{2}{7}\]
\[x = \frac{1}{2} \cdot \frac{7}{2}\]
\[x = \frac{7}{4} \neq \frac{8}{9}.\]
\[\mathbf{Нет.}\]