Try out these interactive websites. They all have math, but most can lead you to other subject preparation, too.
*Background on the GED *Math test information, practice test, and review *Links to flashcards and other sites http://www.gedprepinfo.com
Practice questions with answers and brief descriptions of solving techniques http://www.studyguidezone.com/ged_math.htm
Online course for GED preparation http://testprepreview.com/ged_practice.htm