Long Multiplication using Latex

Question

I am writing a program that generates the steps performed during math operations ( + - * / ) and explain it has well.

I have read this and the best answer here is using the xlop package , which displays, e.g. multiplication as (in plain text):

    3 8 4
x     5 6
---------
  2 3 0 4
1 9 2 0
---------
2 1 5 0 4

And the latex :

\documentclass{article}
\usepackage{xlop}
\begin{document}
\opmul{384}{56}\qquad
\end{document}

But is there a way to create the latex like

    3 8 4
x     5 6
---------
  2 3 0 4

Here is one way using Plain-commands:

\vbox{
  \openup2pt
  \def\trule{\noalign{\smallskip\hrule\smallskip}}
  \halign{&\tabskip1em$\mathstrut#$\cr
          &   & 3 & 8 & 4 \cr
    \times&   &   & 5 & 6 \cr
    \trule
          & 2 & 3 & 0 & 4 \cr
    \trule
  }
}
\bye

Where it is not completely finished but shows a 'step' in the process. So what I mean is that , is it possible using the xlop package to specify to which degree and what it completed or what I want to omit from the output ? Or do I need to use a totally different technique

Answer 1

There are some options for this in xlop, some more easy than others. Some times is good idea take a look to the manual of the packages.

---

\documentclass[a5paper]{article}
\usepackage{xlop,geometry}
\newcommand\hole[1]{_}
\begin{document}
\sffamily
\noindent
\begin{minipage}[c][3cm][t]{.16\linewidth}
\opmul{384}{56}
\vfill full result

\end{minipage}
\hfil
\begin{minipage}[c][3cm][t]{.16\linewidth}
\opmul[displayintermediary=None]{384}{56} 
\vfill shortened 
\end{minipage}
\hfil
\begin{minipage}[c][3cm][t]{.16\linewidth}
\oplput(2,-0.7){3}\oplput(3,-0.7){8}\oplput(4,-0.7){4}
\oplput(1,-1.2){$\times$}
\oplput(3,-1.7){5}\oplput(4,-1.7){6}
\ophline(0,-1.95){5}
\oplput(1,-2.7){2}\oplput(2,-2.7){3}\oplput(3,-2.7){0}\oplput(4,-2.7){4}
\vfill\small\raggedright hard way, wrong or incomplete?
\end{minipage}
\hfil 
\begin{minipage}[c][3cm][t]{.16\linewidth}
\oplput(2,-0.7){3}\oplput(3,-0.7){8}\oplput(4,-0.7){4}
\oplput(1,-1.2){$\times$}
\oplput(3,-1.7){5}\oplput(4,-1.7){6}
\ophline(1,-1.95){4}
\oplput(1,-2.7){2}\oplput(2,-2.7){3}\oplput(3,-2.7){0}\oplput(4,-2.7){4}
\oplput(0,-3.7){.}\oplput(1,-3.7){.}\oplput(2,-3.7){.}\oplput(3,-3.7){.}\oplput(4,-3.7){←}
\ophline(0,-3.95){5}
\vfill\raggedright hard way,\ but clear
\end{minipage}
\hfil
\begin{minipage}[c][3cm][t]{.16\linewidth}
\opmul[intermediarystyle.2=\hole,resultstyle=\hole]{384}{56}

\vfill\raggedright easier and better?
\end{minipage}
\end{document}