A far from optimal workaround for adding formulas to google presentations and properly also google docs is to use
http://www.codecogs.com/latex/eqneditor.php
to construct the formula with latex syntax and load it as an image by adding an image from an URL E.g.:
formula generated by codecogs.com
The ugly drawback is that, AFAIK, you are not able to recall the link address and change your formula. But for at quick, one time workaround I think it works
Tags: equation, google docs, latex, presentation