My question is about possible advantages of writing
$\mbox{\textit{Re}}=\SI{0.137}{}$
instead of
$\mbox{\textit{Re}}=0.137$
Is there any?
The \num
command is provided primarily to allow consistent number formatting with the first argument to \SI
. Thus whether you want to use \num
is primarily about whether you need that consistent formatting. For example, \num
will do things like turn ,
into .
(as standard) to produce normal scientific output even if the input is localised. It will also turn 1.2e3
into 1.2 \times 10^{3}
and so forth.
Of course, if you choose to turn off the number parser in siunitx
then the format of numbers is the same between $1.23$
and \num{1.23}
. (Indeed, while people mainly ask about number formatting the real core point of siunitx
is not that but the idea of consistent application of units.)
\textit
or better,\mathit
\num{<number>}
macro so you don't need to skip the unit.\SI
if you just want a number: they are semantically different.decimalsymbol
option, if you are writting in spanish and you don't want to use the international format. Just load\usepackage[decimalsymbol=comma]{siunitx}
babel
for some reason switches it to comma.