I have to agree with everyone! I have been teaching GED preparation for 11 years and the math test is probably the hardest! Why, I'm not sure except that perhaps many students hated math when they were in school, and that math anxiety has followed them into adulthood.
One thing that I have found is that if a student is having difficulty with the math test, the best way for studying it is to find a good math book. You may want to start with a pre-ged math book, not because you don't know the basic math, but because many students need to build their confidence. Then move to a higher level GED math book.
I books I would recommend would recommend are Top 50 Math Skills for GED Success and Steck Vaughn's Pre-GED math book. http://stores.ebay.com/Learningtrends_GED
My Math Help Blog: http://www.learningtrends.com/gedhelp.htm