# How to get two columns in equation

This is my code:

\begin{align*}
\le \left|\frac{(0,128568071\ \mathrm{\frac{W}{mK}})^2\cdot (0,003686\ \mathrm{m})^2+(0,2709520216\ \mathrm{\frac{W}{mK}})^2\cdot (6,348\cdot 3,686)10^{-3}\ \mathrm{m}}{0,128568071\ \mathrm{\frac{W}{mK}}\cdot 6,348\cdot 10^{-3}\ \mathrm{m}+0,2709520216\ \mathrm{\frac{W}{mK}}\cdot 3,686\ \cdot 10^{-3}\ \mathrm{m}}\cdot 0,004667699579\ \mathrm{\frac{W}{mK}}\right|
\end{align*}


and it looks like this

How can I split the equation into two columns such that the entire equation fills on the paper? I'm taking absolute value of the equation that makes splitting harder.

• Welcome! Please add a self-contained compilable example. And what is the benefit from this transcendental accuracy of your floating point numbers, this is not a mathematical table for a geometric function; 4 decimal digits are more than enough! Jan 4, 2019 at 19:21
• Jan 4, 2019 at 20:26

I propose this, which relies on siunitx, the \medmath command, from nccmath and the splitfrac command from mathtools:

\documentclass{article}
\usepackage[utf8]{inputenc}%
\usepackage{showframe}
\renewcommand{\ShowFrameLinethickness}{0.3pt}

\usepackage{mathtools, nccmath}
\usepackage{siunitx}
\DeclareSIUnit{\mK}{\milli\kelvin}

\begin{document}

\begin{align*}
\sisetup{per-mode = fraction, exponent-product = \cdot}
\le \left|{\medmath{\frac{\splitfrac{(\SI{0,128568071}{\W\per\mK})^2\cdot (\SI{0,003686}{\m})^2}{+(\SI{0,2709520216}{\W\per\mK})^2\cdot (6,348\cdot 3,686)\SI{e-3}{\m}}}{\splitfrac{\SI{0,128568071}{\W\per\mK}\cdot \SI{6,348 e-3}{\m}}{+\SI{0,2709520216}{\W\per\mK}\cdot \SI{3,686e-3}{\m}}}\cdot \SI{0,004667699579}{\W\per\mK}}}\right|
\end{align*}

\end{document}