I created a Moodle2Word plug-in to support importing and exporting questions to and from Microsoft Word a few years ago. I have now released an update to this plug-in with support for equations which readers of this forum may be interested in.
If you use Microsoft Word, and either MathType or the native Microsoft Word Equation Editor to insert equations, you can create and import quiz questions into Moodle question banks. The equations will be converted into images when you upload the questions.
Although probably not for the purists, it does at least offer the benefit that equations will render correctly inside Moodle once uploaded. Both MathType and the Microsoft Equation Editor offer a range of input facilities, including wizards, templates and direct TeX entry, so entering equations should be relatively easy for all levels of user.
Further documentation is available at http://docs.moodle.org/26/en/Word_table_format.