最简单,最好……但是用表格来做有什么乐趣呢?:)
\documentclass{article}
\newlength\digit
\def\h#1#2#3{{\parindent0pt\leavevmode%
\settowidth{\digit}{0}%
\hbox to\digit{{\vtop{%
\makebox[0pt][l]{#1}\\%
\makebox[0pt][l]{#2}\\%
\makebox[0pt][l]{#3}}}}}}
\begin{document}
\h6~~\h53~\h521\h42~33
\end{document}