\[Стр.\ 54.\]
\[\boxed{\mathbf{6.}}\]
\[5\frac{1}{3} \cdot \frac{5}{6} = \frac{16}{3} \cdot \frac{5}{6} = \frac{40}{9} = 4\frac{4}{9} -\]
\[произведение.\]
\[5\frac{1}{3} - \frac{5}{6} = 5\frac{2}{6} - \frac{5}{6} = 4\frac{8}{6} - \frac{5}{6} =\]
\[= 4\frac{3}{6} = 4\frac{1}{2} - разность.\]
\[Произведение\ меньше\ \]
\[разности\ на:\]
\[4\frac{1}{2} - 4\frac{4}{9} = 4\frac{9}{18} - 4\frac{8}{18} = \frac{1}{18}.\]
\[Ответ:произведение;на\ \frac{1}{18}.\]
\[\boxed{\mathbf{7.}}\]
\[\textbf{а)}\ 3 \cdot 1 + 3 \cdot 1 = 6\ см^{2}.\]
\[\textbf{б)}\ 1 \cdot 4 + 2 \cdot 1 + 1 \cdot 1 + 1 \cdot 1 =\]
\[= 8\ см^{2}.\]
\[\textbf{в)}\ 3 \cdot 1 + 2 \cdot 1 + 1 \cdot 1 = 6\ см^{2}.\]