GMATQuantum Course
Absolute Value Algebra Algebra AMC Android App angles Area Arithmetic Arithmetic Manipulations Arithmetic Sequence Average Border Careless Mistakes Chords Circles Combinations Coordinate Geometry Counting Cubes Data Sufficiency Decimals Diophantine Equations Distance/Rate/Time Divisibility Double Sets Dvisibility Exam Pack 2 Exponents External Angles Factorial Flexible Thinking Fractional Exponents Fractions Functions Geometric Sequences Geometry GMAC GMAT GMAT Exam Pack 1 GMAT Official Guides GMAT Paper Tests GMAT Quant Review 2016 GMAT Quantitative Review 2017 GMAT Strategy GMAT Verbal GMATPrep GMATPrep 2.0 GMATPrep Exam Pack 2 GMATPrep Exam Pack1 GMATPrep Question Pack 1 GMATPrep Software Hexagon Identities Identities: Difference of Squares Inequalities Integrated Reasoning Integrated Reasoning Intercept Linear equations Lines Maximum Mean Median Mixtures Multiples Number Theory Official GMAT Guide 2018 Official GMAT Integrated Reasoning Prep Tool Official Guide 10 Official Guide 13 Official Guide 14 Official Guide 2015 Official Guide 2016 Official Guide 2017 Official Guide for GMAT Review 2015 Official Guide GMAT 13th Edition Official Guide GMAT 2015 OOfficial Guide for GMAT Review 2018 Overlapping Sets Pacing Parabola Patterns Pentagon Percent Change Percents Permutations Polygon Prime Factors Probability Problem Solving Skill Quadratics Radicals Range Ratio Reading Comprehension Rectangles Remainders Right triangles Score Cancellation sequence Sequences Sequences Slope Statistics System of Equations Triangles Triple Venn diagrams Undefined expressions Venn Diagrams Word Problems YouTube Offline

How effective is plugging numbers when solving GMAT problems?

The video below illustrates how to apply the approach of plugging in numbers to solve GMAT problems, and the limitations of this approach. I also compare the plug in approach to the direct approach. Here is the summary of the key points:

Advantages of Plug in approach:

  • It is easy to implement and the easier algebraic/word problems can often be solved by using simple numbers. 
  • Sidesteps the necessary algebra. This is one of the main reasons why a lot of test prep books recommend plugging numbers because many students are weak in algebraic procedures.

Drawbacks of Plug in approach:

  • The choice of numbers to pick is important, because that can influence the amount and complexity of the ensuing numerical work.
  • In case of difficult problems, the amount of numerical work and the likelihood of making mistakes increases.
  • To be absolutely certain of the correct choice, one needs to test all of the answer choices.
  • In case of very difficult problems, the amount of work may exceed the amount of time it may take to approach the problem directly. 

Advantages of direct algebraic approach:

  • Direct and fast, and no need to spend time in thinking about appropriate choice of numbers. 
  • In case of difficult problems, the most efficient and fastest method is often the direct algebraic approach.
  • In case of data sufficiency problems that require one to translate a particular word statement to an algebraic expression and subsequent simplification, the ability to solve the entire question might rest on being comfortable with the direct algebraic approach.
  • The harder problems often require a strong grasp of algebraic procedures and this skill is necessary to obtain a high score on the GMAT.

Drawbacks of direct algebraic approach:

  • Difficult to implement if one is not comfortable with manipulating algebraic expressions and simplifying them with accuracy.

Reader Comments

There are no comments for this journal entry. To create a new comment, use the form below.

PostPost a New Comment

Enter your information below to add a new comment.

My response is on my own website »
Author Email (optional):
Author URL (optional):
Some HTML allowed: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <code> <em> <i> <strike> <strong>