If a students has a fairly high reading level, at least 10+, they should do fairly well on a GED Practice Predictor test. There are practice tests in all five areas of the GED.
My recommendation is to take a Predictor GED test, in the area that you will be testing, PRIOR to the test date. It will do three things for you: give you a sense of timing (all the GED tests are timed); give you a sense of what will be on the test; and, it will give you an idea of how well you should do on the "official" GED test.
As a general rule, if you score 500 or better on the practice predictor GED test, and you stayed within the time limit..... you should do ok on the "real" GED test.
Where can you find or purchase a predictor test? Check out your local Adult Learning Center or send us an email at firstname.lastname@example.org and we will be happy to quote you a price.