Top 9 GMAT Math Tips


Manhattan Prep GMAT Blog - Top 9 GMAT Math Tips by Chelsey Cooley

Looking for GMAT Math tips that might earn you a few extra points on Quant? Every one of us can use these simple test-day GMAT math tips, no matter what Quant score we’re aiming for.

1. Never miss an easy question on GMAT Math.

You’re going to miss lots of Quant questions on test day. That’s not one of the GMAT Math tips—that’s just a fact of life! The test is designed to force you to miss questions.

However, there’s more than one way to miss a Quant question. On test day, you can divide your GMAT Math mistakes into two categories: ones you couldn’t have gotten right and ones you could have gotten right.

If you just don’t know a piece of GMAT Math, it’s beyond your control on test day. In fact, if you miss a question because you didn’t know something, pat yourself on the back. You recognized that the problem wasn’t going anywhere, and you moved on. That’s how you win those questions.

However, there are a lot of GMAT Math questions that you can get right within two minutes on test day—problems where you already know everything you need to know. Our number-one GMAT Math tip is to never get those problems wrong.

A lot of people do get those ‘gettable’ problems wrong. Why? Sloppy handwriting. Making assumptions. Not double-checking their work. Subtracting where they should have added. These are all within your control on test day! In most areas of life, when we do something hard, we slow down, and when we do something easy, we speed up. On the GMAT, that’s not a great idea. Slow down on the ‘gettable’ problems, because that’s where a few extra seconds and a little extra attention will make a difference. Feel free to speed up on the ‘not gettable’ ones—the problems that totally confuse you. There’s no reason to spend 3 minutes on those problems when you could spend 30 seconds instead!

2. Keep your handwriting large and clear.

Writing carefully will help you with GMAT Math in two different ways. One, it can prevent a few easy mistakes (ever look at a 2 and read it as a 7?). This is especially true on Geometry problems, where a mislabeled diagram can take you straight to the wrong answer. Two, if your handwriting is naturally a mess, writing clearly will force you to slow down and calm down. Slowing down has a real effect on your thinking.

While you’re at it, use this method to organize your whole scratch pad. It will help you control your GMAT Math timing and will keep your scratch work on different problems from running into each other. Try out the elimination method from this article for Data Sufficiency problems, too.

3. Don’t be an A student.

If the GMAT was a college exam, it would be the most unfair exam in the world. If you studied hard and got all of the questions right, the professor wouldn’t give you an A. Instead, she would take that test away and give you an even harder one. She’d keep doing that over and over until you ran out of time, or until your accuracy finally dropped to the C or D level.

GMAT Math is tough for those of us who like to get As in class. You might know intellectually that you won’t get an “A” on the GMAT (because nobody does). But it’s still easy to go into the test thinking like this:

“Oh, I know that other people will get questions wrong on the GMAT, but that’s for people who aren’t going to get a good score. I want a 700, so I’m going to try to get them all right.”

That’s not your smart, rational executive brain saying that. It’s one of your GMAT gremlins. If you listen to it, you’ll end up with a score much lower than 700. If you want a great GMAT Math score, check out this data-based breakdown of how many questions GMAT high-scorers really miss.

4. Don’t panic about probability.

Probability and combinatorics problems are a gift. Why? Because the GMAT doesn’t usually make it obvious which questions you should skip. But if you see a probability or combinatorics problem, that’s GMAT Math giving you permission to skip it right away!

Why do we recommend skipping these questions on test day? It’s not just because they’re often hard and time-consuming. There are two other great reasons to put them on your skip list. First, they don’t show up too often on the test, so skipping them is unlikely to hurt your score. Second, the math you need for these problems usually doesn’t work on other types of problems. So you might end up studying for hours just to get one more problem right on the test.  

That said, if you have time before test day and your GMAT Math goal is a 45 or higher, you should spend one or two hours learning the following:

  • What makes a probability or combinatorics problem easy?
  • How do you solve easy probability or combinatorics problems?

The Number Properties Strategy Guide is a good starting place, and so is this series of combinatorics and probability articles. You can also check out Khan Academy’s section on these topics.

5. Use uneducated guessing.

In this article, instructor James Brock wildly guesses his way through a set of ten GMAT Math Problem Solving problems—and he gets six of them right. If that doesn’t convince you to try his method, nothing will! You can learn to make smart and thoughtful guesses, but on test day, sometimes you just need to get through a problem in fifteen seconds and keep moving. This method will maximize the odds that you’ll get the answer anyways.

6. Watch your posture.

It’s a small trick, but it just might work. If you’re anxious about math, you may be more confident about your GMAT performance if you sit up straight while taking the test. Or try striking a power pose before you walk into the testing center. This weirdly controversial, but extremely simple, technique might boost your GMAT Math confidence.

7. Hack your GMAT Math vocabulary.

As a GMAT instructor, my biggest GMAT Math pet peeves are two simple words: “move” and “cancel.” We often talk about simplifying equations in terms of moving and canceling. For instance, if you’re trying to simplify this equation, you might “move” the -2x to the other side:

4x = 6y – 2x + 3

The problem is, “moving” isn’t math. When you say you’re moving a term to the other side of the equation, you’re not actually thinking about what math you’re doing. Instead, you’re imagining yourself picking up objects and moving them around. That’s totally fine if you’re trying to work something out on the back of a napkin, but it also leaves you vulnerable to careless mistakes, like this one:

4x = 6y – 2x + 3

4x – 2x = 6y + 3

To become more consistent and more precise, turn on your math brain and stop using the word “move.” Instead, think in terms of the math you’re actually doing. In this case, you’re adding 2x to both sides of the equation. If you tend to make careless GMAT Math mistakes, it can even help to write out the actual math, line by line:

4x = 6y – 2x + 3

4x + 2x = 6y – 2x + 3 + 2x

6x = 6y + 3

“Cancel” is similar—you’re not just crossing off like terms! Instead, you’re adding, subtracting, multiplying, or dividing.

8. Put the answer in a box.

Have you ever submitted your answer to a problem, then realized a second too late that you solved for the wrong thing? If this is you, build a habit of using the “answer box.”

When you start solving a problem, one of the first things you write on your paper should be what you’re solving for, in your own terms. It’s fine to write it in shorthand. You might write something like “number of students = ?” or “55% of x = ?”. Then, draw a box around what you wrote and leave it alone for the time being.

Once you think you’ve got the problem solved, look at the answer box again. Deliberately check to make sure that what you solved for matches what you wrote down. If it does, select your answer and move to the next problem confidently.

9. Breathe, read, think, write.

Humans are lousy at multitasking. It’s one thing to listen to the radio while driving or watch TV while washing dishes. But if you ask too much of your brain at once, things fall apart.

One example of this is doing math while reading a problem. If you start setting up and solving equations the second you start reading, you’ll inevitably end up writing the wrong equations sometimes. Then, you’ll have to go back and ‘undo’ all of the work you’ve already done, just to get started on the problem.

Some GMAT Math tips: Start each problem by taking a breath. Your brain needs oxygen! Then, read the entire problem from the very beginning all the way to the end of the answer choices. (Unless it’s Data Sufficiency. Then you should have the answer choices memorized!) It’s okay to jot down facts while you read the problem, especially if it helps you organize your thinking. But don’t try to do math while you’re reading.

Try not to choose a strategy for solving the problem until you’ve read all the way to the last answer choice. The clues for a couple of huge GMAT Math strategies (Smart Numbers and Backsolving) are usually found in the answer choices. If you start doing algebra before you even look at the answer choices, you’ll miss most of your opportunities to use these powerful techniques. 📝

Want more guidance from our GMAT gurus? You can attend the first session of any of our online or in-person GMAT courses absolutely free! We’re not kidding. Check out our upcoming courses here.

Chelsey CooleyChelsey Cooley Manhattan Prep GRE Instructor is a Manhattan Prep instructor based in Seattle, Washington. Chelsey always followed her heart when it came to her education. Luckily, her heart led her straight to the perfect background for GMAT and GRE teaching: she has undergraduate degrees in mathematics and history, a master’s degree in linguistics, a 790 on the GMAT, and a perfect 170/170 on the GRE. Check out Chelsey’s upcoming GMAT prep offerings here.

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