Hi Krista:

I'm sorry to hear about your experience.

It is certainly strange that your actual GMAT performance would be so different from how you tested on PowerPrep and GMATPrep. Do you think that you had let that first difficult math problem throw off your concentration for the rest of the section? From what I've observed, many people put a lot of attention and effort on the first few questions of each section on the GMAT, believing that the first few questions are all that matter in determining the final score for the section. This isn't really the case--while the first few questions are certainly important, if you make a mistake early in the test, there is still time to compensate and ultimately score well. To give a visceral example, I remember on one of my GMATPrep practice tests, I made an error on question two in the math section--I still managed a 50.

Don't let really difficult questions throw off your concentration! You can't let it ruin your focus--after all, it may be an experimental question and not count.

In terms of preparation for the next few weeks--I recommend the Kaplan 800 book as well. It has some good techniques for solving difficult math problems. Also, I would recommend reviewing OG one more time, and re-taking the two GMATPrep tests. In OG and GMATPrep, focus on identifying patterns in test questions. I've noticed that the same patterns are tested over and over again on the GMAT.

I hope that this advice helps. In the end, Krista, you've got to stay mentally strong. If you encounter a really hard question early in your next GMAT, don't let it throw your concentration! You have time to recover, and remember that the question may be experimental.

Best of luck!