Have you looked at the Manhattan Number Properties
book? I use to dread them too, but it that book helped me tremendously. Since your test is on tuesday I would watch the Kaplan
Youtube Video below since its gives a simple DS Strategy to work with. Also beware that you dont get psyched out when you DS Qs. They are just like math questions and part of the test psychology is to scare you. Just think of it as PS question thats hidden in words. Its your job to rephrase(the techniques described above) to draw out the meaning.
Take a look at these resources:http://www.platinumgmat.com/gmat_study_ ... propertieshttp://www.youtube.com/watch?v=3FrJfs59kHM
Video shows the DS Method I use when Solving DS Problems. Its called 12TEN.
Also here is some information to review your the prop. of exponents.http://www.800score.com/guidec5g.html
Lastly heres a link to the GMAT Club Math Bookgmat-math-book-87417.html