答案1
对的,这是可能的 ...
\documentclass{article}
\usepackage{xlop}
\newcommand\hole[2]{#1}
\begin{document}
\opadd[operandstyle.2=\hole{?}]{123}{456} \qquad
\opadd[resultstyle.1=\hole{?}]{123}{456} \qquad
\opadd[operandstyle.1.3=\hole{X},
operandstyle.2.1=\hole{O},
operandstyle.2.2=\hole{O},
operandstyle.2.3=\hole{F}]{789}{112}
\end{document}