[OS X TeX] How to mark = as just a symbol

[Alain Schremmer]

I am running into an error with tcolorbox--a fantastic package--but,  in fact, I suspect that this has nothing to do with the package and just with my general ignorance:

\begin{tcolorbox}[title=$5$]
Text
\end{tcolorbox}

works but

\begin{tcolorbox}[title=$=5$]
Text
\end{tcolorbox}
 

does not. 

I suspect that the second = should somehow be marked as being a mere symbol. Which I don't know how to do.

Embarrassed regards
--schremmer