9800 * 30
$\begin{array}{r}\begin{array}{r}\times \end{array}\underline{\begin{array}{r}\mathrm{9800 }\\ \mathrm{30 }\end{array}}\\ \begin{array}{r}294000\end{array}\end{array}$
 
30200 − 7020 : 10 * 3 + 68 = 28094 + 68 = 28162
$\begin{array}{r}\times \underset{¯}{\begin{array}{r}702\\ 3\end{array}}\\ 2106\end{array}$
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}30200\\ 2106\end{array}}\\ \begin{array}{r}28094\end{array}\end{array}$
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}28094\\ 68\end{array}}\\ \begin{array}{r}28162\end{array}\end{array}$