Whether you are teaching GED math or you are a learner studying GED math to take the GED math test, it is important that you study for the GED math test.
The GED Testing Service has wonderful resources for the math test. It offers a free GED math practice test which will give you an idea of what the "official" test will be like. It also offers other GED math resources such as information on the calculator and the GED formula sheet.
Learningtrends.com offers information as well as free downloadable GED math worksheets. If you look carefully there are also worksheets for science vocabulary.
Worksheetsdirect.com is a member site (currently free) that offers 100's of free math worksheets, including a free fraction course. And, although it is a member site, most of the math worksheets are available with out a membership.
Kahn Academy is a free educational resource for students, parents, and teachers. Resources include math videos and online math practice.
Hope these resources help you as you prepare for the GED.