# Array/tabular for long multiplication

In other topic @egreg helped me a lot but there can be thousand of bugs in horizontal long multiplication. I am a bit frustrated and can't make array like that:

The red drawings are commas. I'm trying to use tabular it's not elegant at all.

• Could you please add a code and a link to "the other topic"? – user156344 Apr 14 at 19:24

Is this what you seek? It uses tabstackengine.

\documentclass[12pt]{article}
\usepackage{mathtools}
\usepackage[TABcline]{tabstackengine}
\TABstackMath
\begin{document}
\tabbedShortunderstack[r]{
&&&&&&&\mathllap{30{,}24\cdot5{,}12}\\
\TABcline{1-8}
&&&&6&0&4&8\\
+\,&&&3&0&2&4&\\
&1&5&1&2&0&&\\
\TABcline{1-8}
&1&5&4&{,}8&3&&&
}
\end{document}


SUPPLEMENT

For cases where there are an even number of lines between the rules, one needs to raise the + half way, here with \+ in lieu of +:

\documentclass[12pt]{article}
\usepackage{mathtools}
\usepackage[TABcline]{tabstackengine}
\newcommand\+{\smash{\raisebox{.5\baselineskip}{$+$}}}
\TABstackMath
\begin{document}
\tabbedShortunderstack[r]{
&&&&&&\mathllap{9{,}37\cdot1{,}90}\\
\TABcline{1-7}
&&&8&4&3&3\\
\+\,&&9&3&7&&\\
\TABcline{1-7}
&1&7&{,}8&0&&
}
\end{document}


• +1, but result should be 154,2 :-) – Zarko Apr 14 at 20:12
• Good but when I have only 2 numbers for addition like most of the time the + should be centered between them like this: imgur.com/a/yPurnum – Simeon Simeonov Apr 15 at 11:52
• @SimeonSimeonov Please see the supplement to my answer. – Steven B. Segletes Apr 15 at 12:14