（2021 秋・龙口市期末）用坚式计算。
$45 \times 78=$
$57 \times 39=$
$432 \div 4=$
$589 \div 8=$
解答】解: $45 \times 78=3510$

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$57 \times 39=2223$

$\begin{array}{r}57 \\ \times \quad 39 \\ \hline 513 \\ 171 \\ \hline 2223\end{array}$

$432 \div 4=108$

$\begin{array}{r}108 \\ 432 \\ 4 \\ \hline 32\end{array}$

$\frac{32}{0}$

$589 \div 8=73 \ldots . .5$

$\begin{array}{r}73 \\ 8 \longdiv { 5 8 9 } \\ 56 \\ \hline 29\end{array}$

$\begin{array}{r}24 \\ \hline 5\end{array}$