\[\boxed{\mathbf{Страница\ 55.\ }\mathbf{Еуроки\ - \ ДЗ\ без\ мороки}}\]
\[\boxed{\mathbf{1.\ }}\]
\[\textbf{а)}\ 12\ :3 = 4\ (длина\ отрезка).\]
\[\textbf{б)}\ 12\ :3 =\]
\[= 4\ (количество\ отрезков).\]
\[\boxed{\mathbf{2.\ }}\]
\[\textbf{б)}\ 45\ 000\ :5 = 9000\]
\[360\ 000\ :900 = 3600\ :9 = 400\ \]
\[\mathbf{Вывод:при\ делении\ круглых\ }\]
\[\mathbf{чисел\ }\left( \mathbf{без\ остатка} \right)\mathbf{\ можно\ }\]
\[\mathbf{сначала\ отбросить\ поровну\ }\]
\[\mathbf{нули\ в\ делимом\ и\ делителе,\ а\ }\]
\[\mathbf{потом\ продолжать\ деление.}\]
\[\boxed{\mathbf{3.\ }}\]
\[2400\ :8 = 300\]
\[49\ 000\ :7 = 7000\]
\[360\ 000\ :4 = 90\ 000\]
\[810\ 000\ :9 = 90\ 000\]
\[2500\ :500 = 25\ :5 = 5\]
\[12\ 000\ :6000 = 12\ :6 = 2\]
\[35\ 000\ :70 = 3500\ :7 = 500\]
\[200\ 000\ :400 = 2000\ :4 = 500\]
\[\boxed{\mathbf{4.\ }}\]
\[\mathbf{a\ :b}\]
\[\textbf{а)}\ a = 84\ 000;\ \ b = 400:\]
\[84\ 000\ :400 = 840\ :4 = 210.\]
\[\textbf{б)}\ a = 9\ 200\ 000;\ \ b = 4:\]
\[9\ 200\ 000\ :4 = 2\ 300\ 000.\]
\[\mathbf{\ }\boxed{\mathbf{5.\ }}\]
\[\textbf{а)}\ 320 \cdot 10\ :40 \cdot 9 =\]
\[= 3200\ :40 \cdot 9 = 80 \cdot 9 = 720\]
\[\textbf{б)}\ 500\ :100 \cdot 60\ :30 =\]
\[= 300\ :30 = 10\]
\[\textbf{в)}\ 750\ :5 \cdot 4\ :100 =\]
\[= 150 \cdot 4\ :100 = 600\ :100 = 6\]
\[\textbf{г)}\ 810\ :90 \cdot 10\ :45 =\]
\[= 9 \cdot 10\ :45 = 90\ :45 = 2\]
\[\boxed{\mathbf{6.\ }}\]
\[10 = 66\ :6 - 6\ :6\]
\[90 = 66 + 6 + 6 + 6 + 6\]
\[100 = 666\ :6 - 66\ :6\]
\[\mathbf{Урок\ 38.\ Решение\ задач}\]