\[Страница\ 8.\]
\[\boxed{\mathbf{4.}}\]
\[\boxed{\mathbf{5.}}\]
\[AB = 4\ см = 40\ мм.\]
\[\textbf{а)}\ 40\ :8 \cdot 3 = 15\ мм\]
\[\textbf{б)}\ 40\ :8 \cdot 7 = 35\ мм\]
\[\textbf{в)}\ 40\ :4 = 10\ мм\]
\[\textbf{г)}\ 40\ :2 = 20\ мм\]
\[\boxed{\mathbf{6.}}\]
\[\textbf{а)}\ 1\ см = \frac{1}{10}\ дм\]
\[1\ ц = \frac{1}{10}\ т\]
\[1\ г = \frac{1}{1\ 000\ 000}\ т\]
\[1\ коп = \frac{1}{100}\ руб\]
\[\textbf{б)}\ 5\ ц = \frac{5}{10}\ т\]
\[38\ м = \frac{38}{1000}\ км\]
\[8\ мм = \frac{8}{10}\ см\]
\[5\ мин = \frac{5}{60}\ ч\]