例1 在下面算式的里填合适的数字。

$\begin{array}{r} 6\ \boxed{2}\\ 7\enclose{longdiv} {\boxed{4}\ \boxed{3}\ \boxed{4}}\\ \underline{\ \ \boxed{4}\ \boxed{2}\ \ \ \ }\\ \ \ \ \ \ \ \boxed{1}\ \boxed{4}\\ \ \ \ \ \ \ \underline{\boxed{1}\ 4}\\ \ \ \ \ \ \ \ \ \ \ 0 \end{array}$