# Math object doesn't display %

Typing the formula

C.I._{95%}

doesn't display the % symbol in the document. It looks just how

C.I._95

would be displayed.

Background: When creating a OpenOffice formula as math object % is often used for special symbols, e.g. %alpha displays the proper Greek symbol. Maybe it's assuming I'm trying to get it to be something else?

Research:

C.I._{95%perthousand}

displays properly (the one that looks like 0/oo).

How do I get the % symbol to show up?

• Do you just want \%? – Svend Tveskæg Oct 6 '13 at 19:07
• Welcome to TeX.SX! In TeX the percent sign % begins a comment extending over the whole line. To escape it use \% instead. – moewe Oct 6 '13 at 19:08

By default the %-symbol is the symbol used to make a comment. To display the symbol you have to "escape" it by prefixing it with \, i.e. \%. The same applies for other symbols, e.g. \$, \{ or \}. The implementation to get the permille symbol was taken from @egreg's answer in Per mille symbol in classicthesis style. # Implementation \documentclass{article} \pagestyle{empty} \usepackage{textcomp} \usepackage{amsmath} \DeclareRobustCommand{\perthousand}{% \ifmmode \text{\textperthousand}% \else \textperthousand \fi} \begin{document}$C.I._{95\%}C.I._{95\perthousand}\$