I want to declare $5\times 5$, so that the spacing comes out right.
When I type $2 \times (8+8+1)$, the spacing next the x is always bigger than that next to the +.
In order to fix this I want to define $\times$ as a binary operator, same as the +.
I try and do this, but that fails.
\DeclareMathSymbol{\xx}{\mathbin}{AMSb}{\times}
$2\xx(8+8+1)$
outputs
2 −1,0,1,−1.3,1.3,−1,0,1 [7] ∗ 2(8 + 8 + 1).
The \times symbol is slightly narrower than +, but (at least in Computer Modern) they have equal width bounding boxes.
Add to this that the shape of \times may make the space after it look a bit wider.
Anyway, \times is declared as a binary operation symbol.
A visual comparison may clear up things:
\documentclass{article}
\makeatletter
\setlength{\fboxrule}{0.1pt} % hairline
\setlength{\fboxsep}{-\fboxrule} % don't add space
\newcommand{\bplus}{\mathbin{\fbox{$\m@th+$}}}
\newcommand{\btimes}{\mathbin{\fbox{$\m@th\times$}}}
\makeatother
\begin{document}
$2 \times (8+8+1)$
$2 + (8\times 8\times 1)$
$2 \btimes (8\bplus 8\bplus 1)$
$2 \bplus (8\btimes 8\btimes 1)$
\end{document}
\mathsurround. It's usually set to zero, but it's good practice to add \m@th for greater safety.
– egreg
Jan 19 '19 at 23:34
xis always bigger than that next to the+” is not true. Please try$2 \times (8+8+1)$\par$2 + (8+8+1)$and you will see that the spacing around\timesis exactly the same as the+. I think you are “tricked” by the symbol itself. The\timeslooks smaller than the+, so you feel that there is more surrounding space. – Ruixi Zhang Jan 19 '19 at 16:37a x bis very common in the text and Latex loves to stretch these occurrences to fix its spacing issues. By limiting its room for maneuvera x bdoes not always look so stretched out all the time. – Johan Jan 19 '19 at 16:59