Conceptualizing versus Calculating on the GMAT
On the GMAT quantitative section, with only about two minutes per question, it is essential that you are able to determine when you actually NEED to calculate an answer, and when you can get to the answer through conceptualization. Extensive calculations take time and provide more opportunities for errors. This does not mean you should never work out the math – on many problems you will need to do so. But it does mean that you want to be able to identify the problems that CAN be solved conceptually.
Data sufficiency problems are the first place to look to avoid calculations. Because data sufficiency problems do not ask you to solve, but rather ask you to determine if you are ABLE to solve, you can often determine if a statement is sufficient without working out all of the math. For example, if you are asked for the average, and a statement tells you the sum of terms and the number of terms, you do not need to actually figure out the average to say that the statement is sufficient.
You can also use conceptualization on problem solving questions in which the answer choices are very far apart. If you can eliminate many of the answer choices because they are clearly too big or too small you can choose the remaining answer choice without doing any calculations. And since the GMAT is adaptive, and continues to get more challenging as you perform better, everyone WILL get stuck on a problem at some point in time, that is the nature of the exam. So if you are stuck, or know you don’t have the time to do a lengthy calculation that you’re not sure is the correct approach anyway, there will be times that you’ll want to use strategic guessing, which can include conceptualizing a word problem, and move on, saving your time for a problem that you are better able to complete correctly.
By looking out for problems in which you can get to the answer without laborious calculations, you will save time and avoid situations in which you can make costly calculation errors and, thus, raise your score. Click here for the Kaplan video on Conceptualization vs. Calculation.