GMAT Quantitative Section Study MethodsApril 3rd, 2018 by Christine Chadwick
When confronting the quantitative section of the GMAT, there are two general areas of focus. The first is an awareness of your specific study habits and test-taking strengths and weaknesses. The second is knowledge of mathematics and peculiarities of the test itself. This guide concerns itself with suggestions for the latter.
The quant consists of 37 questions in 75 minutes, and you cannot go back to change an answer because the computer selects the relative ease or difficulty of the following questions based on your previous answer. There are two types of questions. The problem solving questions include multiple-choice answers with five options, a format familiar to anyone who has taken standardised tests during their educational career. The Data Sufficiency (DS) questions have specific rules that require corresponding strategies. Prepping with the DS in mind is of utmost importance. Use official guides to practice. You'll find that the required mathematics run the gamut from arithmetic to geometry and algebra to word problems. Percentages and properties of integers appear with the highest frequency. In Data Sufficiency, over one quarter of the practice questions provided address either properties of integers or descriptive statistics.
Renew your familiarity with maths diagrams, the figures with problem-solving questions that are supposed to provide information useful in solving the problem. All maths diagrams in the GMAT are drawn to scale unless otherwise specified. However, you cannot assume that any lines or parallels or angles are 90 degrees unless specifically noted. Any rules that apply to calculating area based on parallel lines and right angles do not apply if the relevant lines are "almost" parallel or the angles are "sort of" 90 degrees.
There are two specific strategies to help you with the problems themselves: number sense and a working knowledge of how to estimate. Number sense consists of good intuition regarding what happens to different numbers - positives, negatives, fractions, etc. - when included in specific arithmetic problems. For example, a person with a good numbers sense knows that a large positive number added to small negative number results in a positive, whereas a small positive added to a large negative results in a negative. Number sense includes the knowledge that increasing the numerator of a fraction results in a bigger fraction, whereas a larger denominator results in a smaller fraction, and that multiplying a positive by a decimal smaller than one results in a smaller number, while dividing a positive number by a decimal less than one results in a larger number.
No one is permitted to use a calculator during the quantitative section, so it is on some level a test of your ability to estimate. Estimation is best specifically applied if it's obvious that the question requires savant-level mental calculations. Sometimes the words "approximately" or "in the estimated value of" are included in the text, a clear indicator that estimation is expected. Answers close in range require close attention, but if five multiple choice answers are spread out over a wide range, estimating will get you close enough. Aids in estimation include rounding unwieldy numbers to the nearest whole. Strive to use single-digit calculations whenever possible. For the word problems, particularly those related to finance, look out for answers that indicate implausible returns or other unlikely results.