30000 : 100 * 1000 = 300 * 1000 = 300000
 
30000 : 1000 * 100 = 30 * 100 = 3000
 
286 * 2 − 192 : 3 = 572 − 64 = 508
$\begin{array}{r}\times \underset{¯}{\begin{array}{r}286\\ 2\end{array}}\\ 572\end{array}$
 
$\begin{array}{cc}\begin{array}{l}\underset{¯}{\phantom{0}}192\\ \phantom{0}\underset{¯}{18}\\ \phantom{0}\underset{¯}{\phantom{0}}12\\ \phantom{00}\underset{¯}{12}\\ \phantom{000}0\end{array}& \begin{array}{l}\overline{)3}\\ \overline{\overline{)64}}\end{array}\end{array}$
 
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}572\\ 64\end{array}}\\ \begin{array}{r}508\end{array}\end{array}$
 
805 : 5 + 228 : 4 = 161 + 57 = 218
$\begin{array}{cc}\begin{array}{l}\underset{¯}{\phantom{0}}805\\ \phantom{0}\underset{¯}{5}\\ \underset{¯}{\phantom{0}}30\\ \phantom{0}\underset{¯}{30}\\ \phantom{00}\underset{¯}{\phantom{0}}5\\ \phantom{000}\underset{¯}{5}\\ \phantom{000}0\end{array}& \begin{array}{l}\overline{)5}\\ \overline{\overline{)161}}\end{array}\end{array}$
 
$\begin{array}{cc}\begin{array}{l}\underset{¯}{\phantom{0}}228\\ \phantom{0}\underset{¯}{20}\\ \phantom{0}\underset{¯}{\phantom{0}}28\\ \phantom{00}\underset{¯}{28}\\ \phantom{000}0\end{array}& \begin{array}{l}\overline{)4}\\ \overline{\overline{)57}}\end{array}\end{array}$
 
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}161\\ 57\end{array}}\\ \begin{array}{r}218\end{array}\end{array}$
 
140100 : 100 = 1401
 
140100 − 100 = 140000.