What is mathematics? The great mathematician David Hilbert (1862 – 1943) said, “Mathematics knows no races or geographic boundaries; for mathematics, the cultural world is one country.” That’s great for a brilliant mathematician who, like Hilbert, can survey this entire realm, but what about someone preparing for the GMAT who happens not to have an advanced degree in mathematics? What about someone who now approaches the GMAT, having bid a less-than-fond farewell to math sometime way back in high school? How does someone like this gain access to the country of mathematics?
The good news is that the GMAT does not demand any knowledge of advanced mathematics: trigonometry or calculus or beyond. GMAT Math only covers up to about the level of ordinary Algebra Two and basic Statistics. The challenging part, though, is that the GMAT is not satisfied if you can merely regurgitate math factoids back at it. Rather, the GMAT wants you actually to know the mathematics and be able to reason mathematically. What do I mean?
Many folks think if they know the GMAT formulas, then they know GMAT math. Even the GMAT OG has a “Math Review” in which it lists all possible math factoid tested. Are the contents of that OG’s “Math Review” identical to the mathematics you need to know? Not quite. The factoids themselves are not math, just as isolated pieces of vocabulary do not constitute fluency in another language. Mathematics is using those factoids, exploiting their logical interconnections, and employing them ingeniously as tools for problem-solving. The best GMAT books will begin to give you this latter perspective on math.
Relatedly, stop wondering whether you can use a calculator on the GMAT. You can’t. Folks who don’t understand what math is think that a calculator “does math” for them. No. Instead, when you don’t have a calculator, you are forced to think mathematically. For example, you might use the information about a number’s prime factors to figure out by what one of its powers is divisible. Not having a calculator makes more relevant the divisibility patterns, estimation, and calculation shortcuts like the doubling & halving trick. In fact, whenever you think a GMAT Quant problem is asking you to do a gigantic calculation, you inevitably are overlooking some particularly elegant simplification.
You don’t need to be a math genius to do well on the GMAT Quant section. Furthermore, despite whatever GMAT-IQ correlation there may be, you don’t need to be in the elite IQ region in order to get an elite GMAT score. You just need to work hard. You need to follow a thorough and well-founded GMAT study plan. You need to use excellent GMAT prep resources. You need to put in hours of practice. Math is not a spectator sport: you learn it only by doing it. You need to learn to see patterns, and use these patterns in problem-solving. You need to practice, make mistakes, read solutions & explanations, and learn consistently from your mistakes. This assiduous work, and nothing less, is your passport to GMAT math.