Articles published in Algebra

What Your Math Teacher Didn’t Tell You About PEMDAS

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Manhattan Prep GMAT Blog - What Your Math Teacher Didn't Tell You About PEMDAS by Chelsey Cooley

Did you know that 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.


Here’s a phrase that might bring back some memories from middle school math class: Please Excuse My Dear Aunt Sally, or PEMDAS. (If you went to school outside of the U.S., you may have learned the acronym BEDMAS or BODMAS, instead.) You use this phrase to decide what order to do mathematical operations in: Parentheses first (from inside to outside), then Exponents, then Multiplication and Division (left to right), then Addition and Subtraction (also left to right).

PEMDAS isn’t terribly fancy stuff. It’s just a useful little tool that helps us communicate clearly—it’s what tells us, for instance, that “2x(3+4)” means something different from “2×3 + 4.” But if there’s one thing the GMAT loves, it’s making things look more complicated than they really are. Read more

The GMAT Careless Error Blues (Part 1 of 2)

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Manhattan Prep GMAT Blog - The GMAT Careless Error Blues (Part 1 of 2) by Emily MadanDid you know that 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.


You know the concept, the setup, the steps. You have equations ready and a prowess with algebra. You solve the problem and come up with what is certainly the correct answer, yet you quickly find that answer is not one of the answer choices. You, my friend, are in danger of having just committed a careless error. Read more

Two Minutes of GMAT Quant: A Breakdown (Part 3)

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Manhattan Prep GMAT Blog - Two Minutes of GMAT Quant a Breakdown Part 3Did you know that 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.


Ready for the long awaited conclusion of how to tackle a quant problem in two minutes? We’ll finally get to the point where you can submit an answer! If you haven’t been keeping up, catch up here. Read more

Taking the new mini-GMAT for EMBA? Here’s how to prep! – Part 2

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Manhattan Prep GMAT Blog - Taking the New Mini-GMAT for EMBA Candidates? Here's How to Prep (Part 2) by Stacey KoprinceDid you know that 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.


Last time, we talked about the IR and Verbal sections of the new Executive Assessment (EA) exam for EMBA candidates. Today, we’re going to dive into Quant and also talk more about your overall study. Read more

Think Like an Expert: How & When to Work Backwards on GMAT Problem Solving

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Manhattan Prep GMAT Blog - Working Backwards on GMAT Problem Solving by Ceilidh EricksonDid you know that 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.


What does it take to be a GMAT expert? It’s not just content knowledge (although of course that’s necessary). A GMAT expert knows how to quickly identify patterns and choose quickly from a variety of strategies. In each of these segments, I’ll show you one of these expert moves and how to use it. Read more

Two Minutes of GMAT Quant: A Breakdown – Part 2

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Manhattan Prep GMAT Blog - Here's How to Use Your Two Minutes on GMAT Quant Part 2Did you know that 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.


If you read the first post in this series, then you already know how to get the most you can out of the first 5 seconds of a GMAT Quant problem. But what about the other 1:55? Let’s continue to delve. Read more

Here’s How to do GMAT Unit Conversions Like a Pro

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blog-metricsSometimes the whole point of a specific GMAT problem is to convert between miles and kilometers, or meters and centimeters. In other problems, you’ll need to do a unit conversion as part of a longer solution. It’s easy to mess up unit conversions, and the GMAT writers know this — they include them on the test in order to test your level of organization and your ability to double-check your work. Here’s how to add fast unit conversions to your repertoire of skills.   Read more

Manhattan Prep’s GMAT® study app is now available!

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I am very excited to announce that our new GMAT® study app is available on both iOS and Android!


Download now!

iOS

Android


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How to Tackle Every Single GMAT Problem (Seriously!) – Part 2

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Last time, I introduced you to a set of principles that tie together everything we need to do on the GMAT.

Blog-Tackle-Pt2

If you haven’t already read that article, go ahead and do so now.

Here’s our framework again:

228 - Q Process 3

Today, we’re going to try this out on a Data Sufficiency problem.

Try this DS problem from the GMATPrep® free exams.
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When Your High School Algebra is Wrong: How the GMAT Breaks Systems of Equations Rules

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2-17-HighSchool-2If you have two equations, you can solve for two variables.

This rule is a cornerstone of algebra. It’s how we solve for values when we’re given a relationship between two unknowns:

If I can buy 2 kumquats and 3 rutabagas for $16, and 3 kumquats and 1 rutabaga for $9, how much does 1 kumquat cost?

We set up two equations:

2k + 4r = 16

3k + r = 9

Then we can use either substitution or elimination to solve. (Try it out yourself; answer* below).

On the GMAT, you’ll be using the “2 equations à 2 variables” rule to solve for a lot of word problems like the one above, especially in Problem Solving. Be careful, though! On the GMAT this rule doesn’t always apply, especially in Data Sufficiency. Here are some sneaky exceptions to the rule…

2 Equations aren’t always 2 equations
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