It’s often said of the GMAT that creativity is more indispensable to the quantitative section than it is to the verbal section. While this maxim may run counter to expectations, it is indubitably the case that the student able to think about a math problem in a variety of ways will out-perform the student only able to conceptualize the problem in one or two ways. Dexterity is key, and the test-taker who can quickly size up the problem and imagine not just one method of solving it, but several from which he or she can select the best approach, will always have the advantage over the less imaginative student.
Part of thinking about the quantitative section creatively involves abandoning commonly held fixations in favor of more practical solutions. For example, I routinely see students obsess over concepts like standard deviation and combinations and permutations in lieu of more quotidian and seminal topics like arithmetic and algebra. I know that mastering the fundamentals of arithmetic lacks the glamour of tackling that impenetrable probability problem, but the fact of the matter is that it is the arithmetic that will ultimately be your saving grace on the exam. That standard deviation problem you’re increasingly worried about the closer your exam looms? It is not even guaranteed to be on the text at all – and if it is, it is almost certain to be a lot less complicated than you fear. Arithmetic and algebra, on the other hand, are guaranteed to absolutely pervade all aspects of the quantitative section.
I worry about the student who spends several hours studying the finer points of advanced permutation problems when I see them struggling to convert 4/5 into a decimal or shamelessly putting pencil to paper when calculating 13 times 5. These are real hindrances to your success on the GMAT. You’re far better off doing a series of drills to ensure that your basic math skills are up to par than you are fixating on advanced concepts not even guaranteed to be on the exam. This means boning up on your number properties, knowing your multiplication tables backwards and forwards, being familiar with factors and multiples and primes, memorizing your perfect squares and knowing the rules governing radicals and exponents and order of operations. You also need to be able to convert from decimal to fraction to percent, and you need to be able to do all of this with very little mental exertion and in very little time. After mastering basic arithmetic, you should move on to algebra, re-acquainting yourself with arithmetic properties (distributive, commutative, associative, etc), and the fundamentals of algebra, like substitution and combination, quadratic equations and systems of equations. Mastering these concepts is the surest path to your success on the GMAT.