Did you ever have one of those anal teachers in high school math or science who would take off points if you did not include the correct units? So an answer of 7 would only receive partial credit when the answer was 7 inches.  Although this practice likely seemed frustrating at the time, I hope to provide some method behind this madness “ or specifically how awareness of units can help you on the GMAT.

My appreciation of units first began during college. I was a chemistry major in college, and as part of my major I had to take physics.  The topics in physics never came naturally for me so I was always looking for little tricks that would lead me towards a correct answer.  One trick I found that was surprisingly effective was to just combine the numbers in the way such that the answer was in the appropriate units.  For example if the question asked for an acceleration (the rate at which speed is changing or the second derivative of distance for the calculus-inclined), I knew that acceleration is always in the form of units of distance / units of time^2 (e.g. meters/ seconds^2).  So unless I combined the numbers in a way that resulted in these units as the answer “ for example by dividing a speed in meters per second by a time in seconds “ I knew I had done something wrong.

Since units are not required on the GMAT, I find many students exclude them entirely from their note taking and calculations.  But keeping track of units, while it may cost a little time, can help lead you towards right answers and prevent you from doing illogical algebra.
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