Avoid unnecessary work.
Speed is crucial to have a shot at a top 10% GMAT math score, but to
a generation of test-takers more familiar with Palm Pilots than paper
and pencil, the no-calculator clause is a time killer. Learn to
approximate. Learn to avoid long, drawn-out calculations. Above all,
learn to avoid doing math the "traditional" way.
Look at a sample question:
Which is the closest approximation of five billion divided by
397,264?
(A) 12.5
(B) 1,250
(C) 2,250
(D) 12,500
(E) 20,000
In the question above, do you really want to divide anything by
397,264? No! Let's approximate 400,000 and quickly restate the question:
5,000,000,000/400,000=?
Cancel out the zeros and you get: 50,000/4=?=(do the math in your
head!)=12,500=Easy points in mere seconds.
Simplify confusing problems
GMAT word problems are often deliberately confusing, and thus
challenge you to "translate" the words into diagram, sketches, or
equations - anything, in fact, that helps you get the answer quickly and
leanly. You can spot a successful translation because it will put you
only a few seconds away from the solution. If you're avoiding
calculations like we showed you above, you'll be using your scratch
paper almost exclusively to set up problems in this way.
"Hard" GMAT math often tests your reading skills (and your
composure)
Ever heard of a "proverbial"? Of course not! The GMAT
test writers occasionally create "new" math concepts just to see how
well you adapt to the unknown. When you see one of these Frankenstein
monsters, read very carefully and take the question apart step-by-step.
You can often make it even easier by focusing on the answer choices.