How To Do Practice Problems

You should follow me on Twitter. While you're at it, take a moment to subscribe to GMAT Hacks via RSS or Email.


Many, if not most, of the students who come to me for help on the GMAT seem to have designed the same curriculum for themselves: get a bunch of books, do as many practice problems as possible, and success will follow. I've seen it work occasionally, but simply chugging through hundreds of problems won't result in your best possible score on test day.

You've probably heard the saying, "Practice doesn't make perfect; perfect practice makes perfect." When preparing for a high-intensity, high-stress, timed experience like a standardized test, that saying is as true than ever. The trick, then, is using your time to practice perfectly. Unless you're getting every question right in no more time than you should take on test day, it may not be obvious how to accomplish that.

Three steps to planning an effective practice session

The first step is to drastically lower your expectations of how many practice problems you'll do in a sitting, in a week, in a month, or in your entire course of preparation. 500-800 problems, total, may be more than enough to get you ready for the GMAT. If you have a hefty stack of prep books sitting around, you're likely to have at least five times that many at your disposal. Don't do them all.

Second, always practice the same way--the way you'll do questions on the test. Work only on scratch paper; don't write in your book at all. Set up your scratch paper as if you were taking the test, prop up your book so that it's more like you're looking at a computer screen, and set a timer. It's not a race (yet, anyway), but you want to know how close you are to completing problems at the pace that will be required on the actual test.

The third step is to set a reasonable goal for one sitting--and not take a break. Depending on how challenging the problems are relative to your current progress (as well as what types of problems you're working on), the exact number will differ. But even if you have all day, never plan on doing more than about 40 at one stretch. You won't have to do many more than that on the test, so why build stamina you won't need? As you'll see in a few moments, the proper time investment for 40 problems may be far greater than you're currently spending.

How to do practice problems

Here's what you'll do when you start working through problems. Start the timer and work as you would normally. Don't worry about meeting certain time limitations, but when you complete each question, jot down, next to your scratchwork, what your timer reads. Also, of course, write down your answer for each question. Last (this is important), if you have any concerns that the way you approached the question was inefficient, incorrect, or in any way suboptimal, mark your scratch paper with a star.

When you're done with the problems you set out for yourself, pat yourself on the back, get up and stretch, and take a break. You might even let those problems sit for an afternoon or even a day. (But no longer than a day.) The key part of the process begins only after your first time through the problems.

How to review your practice session

When you look back over your scratch paper, three types of problems should jump out at you: the ones you answered incorrectly, the ones you starred (because you thought you could have done them better), and ones that took too long. Getting a math problem right in five minutes may feel good, but that's a largely worthless skill on the GMAT, when you have to answer 37 questions in 75 minutes. You need to learn how to do that question better.

You'll probably find that you missed a few of the questions because of careless errors; perhaps you missed a key "NOT", or failed to carry the one. Maybe the correct path to some of the problems became apparent only after you had worked through it the wrong way. Regardless, for every problem you missed, starred, or took too long the first time through, do it again.

Yep, that's right: do them all again.

Before you do that, though, read through the explanations. There will probably be a few of those that you don't quite understand; if you're working with a tutor, those are among the best potential uses of your time with him or her. If there are problems that you just don't know how to go about, even after reading the explanation, take those off the list and put them aside until you can get help.

If going through the explanations takes a long time, you might need another break before embarking on your second pass through the problems you'll do again. By all means, take a breather and come back fresh. When you do go through the problems a second time, follow the same guidelines you did the first time--scratch paper, timer, the whole works.

Obviously, this process takes some time--much longer than what is required to simply do the problems, glance at the explanations, and move on. The difference in usefulness, however, is enormous.

The positive effect of doing problems this way

When you're doing problems a second time--even ones you'd already gotten right, if they took too long or you weren't sure about your approach--you're pounding the correct method into your head. Your scratchwork, as well, should be perfect--not only will your brain remember the process by which it completed the problem, but it will also seize upon the visual of clean, clear scratchwork. (I'll focus more on how to optimize your scratchwork in a future tip.)

It's not possible to perfectly practice GMAT questions on your first pass. However, it's crucial that you spend a substantial portion of your study time perfectly practicing. Doing problems a second, or even a third or fourth time--correctly, confidently, cleanly, and efficiently--is the best way to accomplish that.



About the author: Jeff Sackmann has written many GMAT preparation books, including the popular Total GMAT Math, Total GMAT Verbal, and GMAT 111. He has also created explanations for problems in The Official Guide, as well as 1,800 practice GMAT math questions.

Total GMAT Verbal

The comprehensive guide to the GMAT Verbal section. Recognize, dissect, and master every question type you'll face on the test. Everything you need, all in one place, including 100+ realistic practice questions.
Click to read more.