Here is a practice grid to help you work through your practice problem sets. I can't emphasize enough how important this grid was in helping me to identify where I was weak and prepare tactically.

When you open this spreadsheet, you will notice the following fields:

• Start time
• Question number
• Answer choices (a, b, c, d, e)
• Feeling on question (slow, not sure)
• Result (correct, wrong, careless error, concept error)
• Notes

Here is how you can use this spreadsheet to analyze your strengthes and weaknesses:

I would try doing forty problems each day of a certain type. For example, I would do forty SC questions, or forty PS questions--I wouldn't mix up problem types. I would give myself a time limit to answer the forty questions, usually an hour. I wouldn't take any breaks, I would just try to answer all the questions consecutively in the time I gave myself.

I would keep a clock nearby and write down the time after every 10 questions in the "Start Time" field to get a sense of how I was keeping pace. I would use this grid to mark off my answer choice, and if a problem was particularly difficult for me, I would sometimes mark the "Slow" or "Not sure" fields so that I could remember that a particular question was hard.

After I had gone through the 40 problems, I would go back and use the answer key to check off questions that were correct or wrong on my grid. If I got something wrong, I would try to classify what kind of error it was in my mind. If it was a stupid error that I shouldn't have made, I would check off "Careless error." If the answer was wrong because I didn't understand it fundamentally, I would check off "Concept error."

Additionally, for each of the 40 questions, I would try to classify the type of problem in the "Notes field." For example, if I were doing a set of 40 math problem solving questions, I would write down the topic being tested, like "Algebra," or "Combinations," or "Arithmetic."

I know that this seems like a really tedious method, but believe me, it helped my preparation dramatically--why?

By using this grid with many problem sets, I was able to identify patterns and see where my strengthes and weaknesses were. For example, perhaps I would notice that I consistently get every Algebra problem correct--this would indicate that I wouldn't need to devote much prep time to studying Algebra because my skills there were solid. On the other hand, I may realize that I got a lot of errors with permutation problems. I see that I mark off "Concept error" here consistently, so I know that I should devote more time to studying and practicing permutations. Just as one more example, perhaps I notice that I get a lot of errors with arithmetic problems, but most of these errors are careless. I would know that I need to slow down more when I do these problems because I'm likely doing them too fast, which tends to promote carelessness.

With regard to marking off time every ten questions, this is helpful to do because you can strategize your time more efficiently for the real test. Maybe you notice that you take a lot of time with RC questions, but breeze through SC questions. Knowing this will help you figure out how to allot your time when you are attacking the verbal section on the GMAT.

Just to reiterate, the grid is a tactical method for practicing/studying for the GMAT. I used it a lot to identify where I could improve. Also, I liked to save my grids so that I could go back and review my errors over and over again.

Here's one last handy tip: when you are reviewing your errors, don't look immediately at the explanations in the answer key. Try to solve the question again to see if you can get the right answer yourself before looking at the explanation. You will learn more solving something yourself than being told how to solve it.

This grid was one of my secrets to scoring well on the GMAT. So now you know!