The WORST Mistake You Can Make in GMAT Studying


gmat mistake

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Has this happened to you? You’re reviewing a practice test, and you look at a question you got wrong. “That was just a stupid mistake,” you say, “I should have gotten that one right. I’ll get it next time.”

That’s not a big deal; we all make stupid mistakes sometimes—momentary brain lapses, skipping steps, or just writing down the wrong thing when we knew the right answer. The problem is that unlike in high school, when your teacher might have given you partial credit, on the GMAT there’s no distinction between almost right and completely wrong! You understood the question, solved it all correctly, but then just clicked the wrong answer? Too bad, that’s still a wrong answer.

Careless errors are the #1 cause of score drops on the GMAT! They cause you to miss easier questions, hurting your score a lot more than not know how to solve the harder ones. The biggest mistake that GMAT students make when studying is not tracking errors from the very beginning.

gmat error log

If you want to improve your score on the GMAT, it’s not enough just to know which problems you got wrong. You need to know why you got them wrong. Think about it this way—if you were just learning to play baseball, and every time you got up to the plate you swung and missed, you wouldn’t just say, “Oh well, my mistake, I missed it.” You’d want to analyze exactly why you were missing it. Did you swing too early? Too late? Above or below the ball? Is your batting stance wrong?

You need to apply that same analysis to your “misses” on the GMAT. Because trust me, those dumb mistakes are not as random as they seem! Sure, sometimes you’ll get a fluke like “why did I say 11 — 4 was 8? Obviously I know how to subtract!” That’s probably not a mistake that you’re likely to repeat. But I’m willing to bet that some of your careless mistakes are actually habitual.

As I said, we all make mistakes, but we’re all prone to different patterns of mistakes. The only way to know which mistakes you’re prone to is to track your errors! (Full disclosure: my #1 stupid mistake is forgetting to flip the sign with inequalities. But I didn’t know this until I started tracking and noticed a pattern!)

How to Track—the Error Log

In order to track patterns, you need to record every mistake you’ve made while studying for the GMAT. Sure, this adds extra work, and it seems really tedious, but it’s really important! Your practice exams and GMAT Navigator can track what you’ve gotten right and wrong, but only you can figure out why.

Keep an Error Log to record these mistakes. You can do it by hand, but I prefer a spreadsheet so that I can sort it by problem type (Data Sufficiency or Problem Solving) or by topic (ratios, probability, divisibility, etc.).

gmat error log

What to track:

  • Problem Type (DS, PS, SC, CR, or RC)
  • Topic (polygons, modifiers, assumption, etc)
  • Problem # and source (OG, practice test, strategy guide)—this is important to track so you can revisit the problem later
  • What kind of error—careless or conceptual?
  • Describe the error in detail.

It’s important to distinguish between careless and conceptual mistakes, because they require different fixes. Be specific about the mistake—it’s not enough just to say “oh, that was just a stupid mistake.” What kind of stupid mistake was it? Or, “I didn’t understand.” What didn’t you understand? What should you have seen/connected?

Mistake Types

  • Conceptual mistakes:
    • didn’t understand what the question was asking
    • didn’t rephrase the right way (or thoroughly enough)
    • didn’t know/remember the rules
    • mixed up rules or applied the wrong rule/formula
  • Careless mistakes:
    • read too quickly/misread the question
    • solved for the wrong variable/question
    • made an arithmetic error (got the wrong sum, product, etc.)
    • performed the wrong operation (multiplied instead of divided)
    • misread your own handwriting
    • skipped a step
    • got it right, but clicked the wrong bubble

If you start tracking from the very beginning, you’ll start to notice patterns before they become bad habits!

Once you’ve identified a recurring mistake, do drill sets to practice employing good skills in that problem area. If, for example, you skip steps in algebraic translations and end up with the wrong answer, practice solving a few dozen equations by writing out every single step. It seems elementary, but you won’t make those mistakes again.

Remember, practice, practice, practice makes perfect! 📝

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ceilidh-erickson-Manhattan-Prep-GMAT-InstructorCéilidh Erickson is a Manhattan Prep instructor based in Boston, MA. When she tells people that her name is pronounced “kay-lee,” she often gets puzzled looks. Céilidh is a graduate of Princeton University and a master’s candidate at the Harvard Graduate School of Education. Tutoring was always the job that brought her the greatest joy and challenge, so she decided to make it her full-time job. Check out Céilidh’s upcoming GMAT courses (she scored a 760, so you’re in great hands).

  1. Manpreet January 24, 2013 at 2:47 am

    This is exactly the article i was looking for, this happens to me all the time i make a lot of careless mistakes in the exam and feel i can gain 60 pts more if i avoid those in the real test.This can be a life saver, as i been making a error log but of a different kind . Writing the silly mistakes can be really helpful and i will start doing it from now as my exam is scheduled for march 2013. Hope it does help me!!

    Thanks for the post!

  2. Ceilidh Erickson January 23, 2013 at 12:42 pm

    Reading the question too fast is a VERY common mistake! When we’re pressured, we want to rush. But you never actually save time by rushing through the question. Usually, the best way to save time is to read the question carefully, think about it for a sec, then realize some shortcut that will allow you to avoid the computation, algebra, etc.

    That, and a quick double-check – “did I answer the right question?” – won’t take much extra time, but it can be a lifesaver.

  3. Ceilidh Erickson January 23, 2013 at 12:39 pm

    Aadi, recognizing the patterns is more than half the battle! For certain issues, such as flipping the sign, it’s enough just to tell yourself – “remember to flip!”

    For other issues, like mistakes in addition or subtraction, it’s not quite as easy. Recognizing the issue can help you to slow down and take your time with computation, but that might not be enough. Try to find ways to incorporate math into your daily life! It might sound overly simply, but pick up an elementary school math drill book, and do these kind of drills every day, until it’s second nature.

  4. Marco January 23, 2013 at 8:20 am

    Excelent post! Actually this is my second week of studying, and I think this is the right time to correct careless errors. During my practice I useed to read the question very fast (time pressure) and it may sound stupid but I don’t answer what its been asked. The error log will definitely do the job 🙂 thanks!

  5. Aadi January 23, 2013 at 7:44 am

    This post came at just about the right time for me. I am into the 3rd week of my GMAT prep. After Analyzing my practice test, I and noticed that I made about 10 careless mistakes “Not flipping signs when moving numbers over inequality “, choosing the incorrect option in DS and worst of all getting basic subtraction wrong !
    I was a little embarrassed and kept telling myself that I won’t commit these mistakes as long as I do more drills/problems. The reality, I haven’t been able to fix them.

  6. Ceilidh Erickson January 22, 2013 at 10:59 am

    Ryan, I can certainly empathize! We all have funny little glitches like that. Once we recognize them, then we can remind ourselves, “ok, is that multiplication, or an exponent?” Sometimes recognizing it is enough, but you can practice different fixes, like actually writing the carrot ^ in your notes.

  7. Ryan January 18, 2013 at 3:21 pm

    So true. I used to mess up a lot by writing “4y” on my paper when I saw “4^y” on the screen. I finally realized it, but this post could have saved me a lot of trouble!