math-modemath-operators
How do I present vertical (columnar) multiplication and addition in LaTeX.
Like this:
http://mathworld.wolfram.com/LongMultiplication.html
3 8 4
x 5 6
---------
2 3 0 4
1 9 2 0
---------
2 1 5 0 4
I used the "array" environment. But i have right align problem. Any other best ideas?
As Pieter pointed out, the correct way to define argmin and argmax operators in LaTeX is:
\usepackage{amsmath}
\DeclareMathOperator*{\argmax}{arg\,max}
\DeclareMathOperator*{\argmin}{arg\,min}
Actually, using the amsopn package would be sufficient but it's loaded by amsmath internally, which is recommended for math typesetting anyway.
The * in \DeclareMathOperator* places the underscored argument underneath the word rather than to the bottom right of it.
The addition is fairly simple and examples can be found at Numbering Vertical Addition Problems.
For the long division in your style you can use an array environment.
The MWE is shown below.
\documentclass[11pt]{article}
\begin{document}
% spacing round the bracket in long division
\newcommand\divspace{\,}
\[
\arraycolsep=0em
\begin{array}{r@{\divspace}c@{\divspace}lllll}
& & \multicolumn{4}{r}{2500.}&(answer)\\
\cline{2-6}
25&\big)&\multicolumn{4}{l}{62500.}&\\
& & 50&&&&\\
\cline{3-4}
& & 12&5&&&\\
& & 12&5&&&\\
\cline{3-5}
& & &0&0&&
\end{array}
\]
\end{document}
Best Answer
the xlop package does this sort of thing. It does warn that it uses "french conventions", but at least for multiplication it looks fine, to me.
disclaimer: i last did multiplication sums in school in the 1950s...