The Driving Force Behind Your GMAT Study
If you are like many of us at Veritas Prep Headquarters, you spend a ridiculous amount of time driving, and driving in heavy traffic. But if you find that you are spending too much time driving and not enough time studying for the GMAT, you’re in luck! In a way, driving and the GMAT go hand in hand and there are two major ways that you can use your drive time to become a better GMAT test taker:
1) Driving lets you use a lot of mental, GMAT-style math
2) Driving is a metaphor for GMAT reasoning
Let’s start with mental math. You should know that the GMAT tests a lot of Number Properties, Divisibility and Factors, Rate Problems, and calculations that are done much quicker without doing problems fully by hand. And you should also notice that, while you are driving, you are absolutely bombarded with numbers in that GMAT style. So even if you’re only driving from Los Angeles to San Diego for the weekend, you can sharpen your mental math skills by noting things like:
Speed Limit 65 – 65′s prime factors are 13 and 5
Interstate 405 – because the digits add to a multiple of 9, 405 is divisible by 9. And knowing that, you can do that division in your head by noting that
is 450, leaving 45 left (which is
), so 
32 miles left in your trip – if you are going 60mph you’ll get there in 32 minutes because you are going a mile every minute; if it is 70 you’ll get there in just under a half hour because you’ll do 35 miles in a half hour. And if it’s 80mph, that’s also 80 miles every 60 minutes, so you will go 8 miles every 6 minutes, so because 32 is
you’ll need 4 blocks of 6 minutes, so it will take 24 minutes. You can do all of this in your head to better understand rate calculations.
If a sign says: 21 miles to Irvine; 43 miles to Oceanside; and 72 miles to San Diego – you can factor and divide these numbers in your head, too. 21 is
is prime. 72 is
, and you know that 36 is 6-squared. And 43 divided by 21 is 2, remainder 1. 72 divided by 21…
is 63, leaving a remainder of 9. Again, you can do all of this math in your head while driving, and in doing so you can sharpen your understanding of number properties, factors and multiples, division, rates, etc. And what is more important – the GMAT rewards conceptual understanding of numbers, so this type of study is incredibly effective. The more frequently you can see a number and know multiple things about it (say, 117 – its digits add to a multiple of 9, so it’s divisible by both 3 and 9, and it ends in a 7 so it has to be created by 9 times something ending in a 3, which means it’s
), the more quickly you’ll be able to intuitively break apart calculations on the GMAT.
If you played Tetris as a kid, you undoubtedly remember seeing those shapes falling from the sky in your subconscious. When you learned to type, you likely heard words and instinctively thought about where the letters fell on a keyboard. To become a master of GMAT math, you should train yourself to see patterns, factors, and relationships in numbers just as a force of habit, and driving provides you with a great opportunity to practice that with time that you are not using for any other purpose, anyway.
For the second portion, that driving is a metaphor for GMAT reasoning, think about the last time you were on a freeway. Do you know how you can just *tell* when someone is going to try to cross two lanes at once? Or that when you are about to change lanes from the right to the middle, a car in the left is probably about to fill that space you are after? Or just when a driver isn’t looking and is going to pull into your lane without realizing you’re there? Even when the official signals – blinkers, horns – aren’t there, most of us can instinctively pick up on small clues or tendencies and without formally thinking about it we can be ready to react.
The GMAT is similar — while there are indeed blinkers and horns to blatantly call out many things on the test, those who succeed most can take the test by feel, having paid enough attention while studying to recognize small clues like:
nonnegative –> you’d better believe that 0 (a number that isn’t positive but is also not negative) is likely to be in play
xy > z –> when you see inequalities that ask you to multiply or divide by a variable, there is very high chance that negative numbers will be in play
“only” in a conclusion on CR –> that conclusion is going to be a lot more specific than the average test-taker would think, so that word will be important
“we should restructure the workday so that people can get more sleep” –> that word “restructure” will be key, because people are likely to think of shortening the day
Choice (A) in an SC problem is strangely-worded –> there is a good chance that the author wants you to eliminate based on a structure that you don’t like, but that isn’t necessarily “wrong”, so you’d better wait until you’ve seen another answer choice or two to see what they’re really testing
We live in a GPS, information-overload world in which we are becoming accustomed to having directions dictated to us step-by-step. The GMAT isn’t a step-by-step directions test, though – it’s testing your ability to reason and to pick up on subtle hints and tendencies.
So as you study you must think deeper than “these were the steps to solve this exact problem” and start to feel out how the question was made interesting. Which words or elements of the question might have tricked someone. What else could they have done in the question to add a little nuance and difficulty? What is this question really *about*, other than just “math”?
The GMAT is a lot like driving — to do it well, you need to be defensive, you need to see and anticipate possibilities, and you need to pick up on subtle clues and tendencies to avoid trouble. Train yourself to be aware and use your drive time to sharpen your mental math skills, and your next exit will lead you to an elite business school. Just remember to stay in the right lane so you don’t cut people off while getting there…


2 comments
Pradebban on April 23rd, 2012 at 10:46 am
I think there is a typo. 45*9 =405 and not 55*9 = 405. Thanks for the article!
Anil on April 23rd, 2012 at 12:00 pm
Sharp! Very neatly put. I used to do that when I was in school.
For necessary action: In the statement given below
Interstate 405 – because the digits add to a multiple of 9, 405 is divisible by 9. And knowing that, you can do that division in your head by noting that 9*50 is 450, leaving 45 left (which is 9*5), so 55*9 = 405.
I think it should be 495 instead of 405 and
it should NOT be 'leaving 45 left'