2 Math and Eqn numbering

In the pdf, this will not have a number but in the html it will.

\[ \AA^\top\BB \] You can use nonumber if you need the equation numbering to be the same in html and pdf.

\[ \AA^\top\BB\nonumber \]

If we want to crossref an equation, use equation environment and escape the ref command so it looks like \\ref{}. This is Equation \ref{eqn1}. \[\begin{equation} \AA^\top\BB \label{eqn1}\end{equation}\]

This is Equation \ref{eqn1}.