\[\boxed{\mathbf{Проверочная\ работа\ №4.\ Повторение:задачи\ на\ дроби}}\]
\[\boxed{\mathbf{1.}}\]
\[12 \cdot \frac{2}{3} = 4 \cdot 2 = 8.\]
\[\boxed{\mathbf{2.}}\]
\[2\ м = 200\ см:\]
\[200 \cdot 0,3 = 60\ см.\]
\[\boxed{\mathbf{3.}}\]
\[12\ :\frac{2}{3} = 12 \cdot \frac{3}{2} = 6 \cdot 3 = 18.\]
\[\boxed{\mathbf{4.}}\]
\[8\ :0,4 = 80\ :4 = 20.\]
\[\boxed{\mathbf{5.}}\]
\[1,2\ :0,04 = 120\ :4 = 30\ раз.\]
\[\boxed{\mathbf{6.}}\]
\[13\ :19 = \frac{13}{19}\ часть.\]
\[\boxed{\mathbf{7.}}\]
\[Нет.\]
\[\frac{1}{5} \cdot \frac{1}{4} = \frac{1}{20}\ м^{2}.\]
\[\boxed{\mathbf{8.}}\]
\[Нет.\]
\[20 \cdot 5 = 100\ рублей.\]