Put plus, minus, time and divide sign in a square

Question

For circumscribed circle, it is $\otimes$, $\ominus$, I get it, but how do you put them inside a square?

i have seen something similar in here and here.

Answer 1

Loading the amssymb package, you can use some commands

\documentclass[varwidth, margin=10pt]{standalone}
\usepackage{amssymb}

\begin{document}
$\boxtimes$ \par
$\boxplus$ \par
$\boxminus$ \par
\end{document}