答案1
这是我的解决方案,虽然不太接近但确实有效 ^^
\documentclass[varwidth,border=7pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{calc, bending}
\usepackage{amsmath}
\def\da#1{\tikz[baseline=(A.base)]
\draw[red, -stealth, line width=.035em]
(0,0) node[circle, inner sep=0cm](A){$#1$}
let \p1=(A.north east),\p2=(A.south west), \n1={\x1-\x2} in
(180:\n1) arc(180:0:\n1);}
\def\ua#1{\tikz[baseline=(A.base)]
\draw[red, -stealth, line width=.035em]
(0,0) node[circle, inner sep=0cm](A){$#1$}
let \p1=(A.north east),\p2=(A.south west), \n1={\x1-\x2} in
(-180:\n1) arc(-180:0:\n1);}
\newcommand{\red}[1]{\color{red}{#1}}
\newcommand{\du}[2]{\underset{\underset{\red{:#1}}{\ua{\phantom{+}}}}{\overset{\overset{\red{:#2}}{\da{\phantom{+}}}}{=}}}
\begin{document}
\[
\frac{36}{60} \du{2}{2} \frac{18}{30} \du{2}{2} \frac{9}{15} \du{2}{3} \frac{3}{5}
\]
\end{document}