\documentclass{article}
\usepackage[paperheight=105mm,paperwidth=74mm,margin=4mm]{geometry}
\pagenumbering{gobble}
\setlength{\parindent}{0pt}
\usepackage{libertinus}
\usepackage{fontspec}
\usepackage{relsize}
\usepackage{unicode-math}
\usepackage{siunitx}
\begin{document}
\fontsize{12}{16}
\selectfont

Math mode manners:
\setmathfont{STIX Two Math}
\[\mathlarger{\begin{aligned}
  f(x) & = a\prime + b\dprime + c\trprime \\
  f\prime(x) & = x^{2} + 1
\end{aligned}}\]

\setmathfont{Libertinus Math}
\[\mathlarger{\begin{aligned}
  f(x) & = a\prime + b\dprime + c\trprime \\
  f\prime(x) & = x^{2} + 1
\end{aligned}}\]

Prose poses problems:
\smallskip

\raggedright{
  60*10'16"N 24*55'52"E (plain)\break
  60°10′16″N 24°55′52″E (unicode)\break
  \ang{60;10;16}N \ang{24;55;52}E (idiomatic)
}
\end{document}
