Equations can get reference numbers using the \tag{} macro, e.g: \[E=mc^2\tag{1}\] produces \[E=mc^2\tag{1}\] Note that the contents of \tag{} are in text mode, so if you want to include math symbols, use \tag{$...$}. E.g., \[E=mc^2\tag{$\bullet$}\] produces \[E=mc^2\tag{$\bullet$}\]