# Spaces between operators and numbers in textmode

I just found the package siunitx which also handles the formatting of numbers quite nicely. It even allows for putting an operator before the number, which is quite practical in texts. I am not sure about the spacing between operator and number, however. See this MWE:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}

\usepackage[per-mode=symbol,detect-all]{siunitx}

\setlength{\parindent}{0em}
\setlength{\parskip}{1cm}

\begin{document}
Text mode:\\
In den anderen Ableitungen zählt jeweils eine Hebung von \SI{\ge 0.1}{\milli\volt} für beide Geschlechter als STEMI-Zeichen (White H et al., 2014).

Math mode:\\
In den anderen Ableitungen zählt jeweils eine Hebung von $\ge\SI{0.1}{\milli\volt}$ für beide Geschlechter als STEMI-Zeichen (White H et al., 2014).
\end{document}


In the output, there is no space between \ge and 0.1 mV in the first paragraph, while it is there if I use \SI{0.1}{\milli\volt} in math mode.

So, which version should I use to get it right? There certainly must be a rule about the spacing of operators and numbers in normal text -- is there?

• Try the same \SI input in text and math mode :-) Sep 6 '16 at 12:43
• @JosephWright OK, both versions look identical now, no spaces. What I meant was more like is there a rule that if you have a complete formula (even one as simple as $a>b$) there must be spaces in the output, and if you are using just an operator and a number in normal text, spaces have to be removed? Sep 6 '16 at 12:58
• I think part of what may be happening in the first example is that the space after \ge is ignored, since it is functioning to signal the end of the command (compare with \S A to produce §A--you wouldn't want a space in the output, but typing the space tells LaTeX that the command is finished). If you want a space after a command, you need to force it: \ge\ . In math mode all spaces are ignored anyway, which is why you get the same output for both expressions in math mode. Sep 10 '16 at 5:42