Estimations

The SBC GMAT Files

General Strategies For Quant: Estimations: Why An MBA Is Not An MSc. Part I

Business truly is a magical field. Psychology, Sociology, Economics, Mathematics, Statistics… so many different fields of knowledge, all rolled  into one. You could spend a lifetime mastering the many different skills one needs to be an excellent and adept business leader. Obviously, no big, successful corporation is a one-man show; the many facets of good business administration require diverse abilities. Any major business decision evolves going through a number of steps, beginning with a vision or concept, through evaluation and planning, and ending with field implementation. Somewhere along the way, a fair amount of number crunching is also necessary – so obviously someone along the pipeline needs to have his math skills at the ready.

Here’s the news flash though – top business schools aren’t looking for that guy; they’re looking for the person who tells him (or her, as the case may be) what to do. Top business schools are looking for future CEOs, and CEOs don’t need to be mathematicians.

Although business isn’t formal mathematics, it does demand solid quantitative adeptness, and the ability to handle numerical information. Working with numbers, at any level, requires one to feel comfortable with them. This twofold purpose is reflected in the GMAT:  the GMAT quantitative section and the upcoming integrated reasoning section (obviously) involve numbers, but they’re not a math exam. The GMAT uses numbers to test our problem solving capabilities and our logic.

Simultaneously, using numbers allows the test to reveal how comfortable we are with them.
Failing to understand the difference between formal mathematics and the GMAT Quant section often leads to unnecessary nitpicking when you solve questions, which amounts to much wasted time – your most valuable resource on this test. For the vast majority of GMAT aspirants, years of formal mathematical training have implanted an urge to algebra-tize that is so well-entrenched, it can be near impossible to resist. And yet, resisting the instinctive urge to express everything in the form of an equation is one thing you must do to succeed.

Estimation & Elimination
Measuring up quantitative information doesn’t require calculating values to the last decimal. On the GMAT, as in business, our goal is to reach the right decision in the minimum time. Efficient problem solving actually means bypassing lengthy calculations by using estimation, while exploiting the multiple choice question format to one’s best advantage by eliminating wrong answer choices.

To embody these principles, GMAT questions are constructed radically differently from traditional math problems. Since the emphasis is on problem solving, more often than not, the question will require only a minimal use of calculation and algebra. In fact, some questions are actually written with estimation in mind – they directly test our capability to ignore the intricacies and focus on the bigger picture. Familiar examples are problems with ugly decimals that ought to be rounded, or problems that explicitly ask for approximations.

But the usefulness of this approach is most apparent in Data Sufficiency questions: a DS question requires you to use mental shortcuts to figure out whether a problem is solvable. In this sense, you are required to envision the structure of the solution, without actually carrying it out. Effectively solving these problems means we need to feel comfortable with leaving the math untended – something many test takers have a hard time getting used to.

Finally, estimation is crucial even in problems that aren’t about rounding decimals and approximation. In some problems, the test taker can use estimation and elimination to narrow down the options, turning a difficult problem into a much simpler one. In the next article, we’ll take a closer look at the importance of estimation and elimination in the GMAT by breaking down real Official problems – stay tuned. For now, keep these three crucial point in mind, next time you face a tough Quant problem:
It’s easy to confuse GMAT Quant with math proper. Old entrenched habits can be serious time-wasters. Don’t jump on every equation you see.

Estimation isn’t a trick, or a cunning shortcut that replaces the ”˜proper’ solution; GMAT questions are written to be amenable to efficient problem solving techniques. On the GMAT, estimation is a valid solution technique, quite often the recommended one.

GMAT problems are multiple choice. Don’t forget to consider the answer choices: they provide clues as to which approach to take, and what degree of accuracy is needed.

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