One of the most popular “tricks” and “hacks” for the math section of the SAT is to avoid actually doing math and instead to pick a number like 1 or 2 and substitute it for a variable to see if it happens to yield a unique answer that matches exactly one of the answer choices.
Let’s be absolutely clear: This is not doing math.
Not only is it not doing math, it’s an insult to your own intelligence and your ability to take on the challenge of learning new skills. It’s an avoidance tactic, justified with the nonsense rationalization that the best way for you to get to the other side of the test is to sneak around it, not go right through it.
We think better of you, and you should, too. The fact is that the math on the SAT is not difficult. The complexity of the problems on the test is, by design, capped. We have to repeat this point: There are no really hard math problems on the test. That means you can learn every math skill needed to get every math problem correct on the test by actually doing the math that the test is assessing.
We also want to make a point of stressing that this tactic, because it’s not actually a mathematical solving method, is not at all guaranteed to produce the right answer; there might be multiple answer choices that evaluate to the same value, or there might be a division by zero condition encountered. Furthermore, plugging in can be far more time-consuming than simply doing the math would be, and it can involve many more steps, heightening the probability of an error creeping in. That’s what trying to evade rigor gets you, and that’s a broad principle that students should really take to heart.
Let’s look at an example:
Let’s try solving this by plugging in for . First, we need to evaluate the provided expression:
Now, we have to plug in in each of the answer choices to see which one(s) match:
Both choices A and D evaluate to 30, so we are not done. If we’re going to stick with plugging in, we’ll have to try another value and hope that it discriminates between these two answers. Let’s go with ; first, we have to re-evaluate the original expression with the new test value:
Now we have to evaluate the expressions in choices A and D to see if exactly one of them also is when :
Only choice D matches, so, at long last, we have our answer.
How would we solve this by actually doing mathematics? We will notice that we have two terms that have a common factor of , so we’ll simply factor the expression:
We trust that it is eminently obvious that just doing the math is dramatically faster and simpler than is using the plugging-in method. Now, you might say, “that’s an extremely contrived example; no one would suggest plugging in here,” but you’d be wrong; we’ve seen the plugging in method recommended for problems of precisely this type, and it’s not explained how a student could use any other method for solving; the assertion is that it’s easiest to try plugging in numbers.
This is not an isolated example, either. Many tutors and even SAT math books advise students to use this approach for all sorts of problems rather than to simply learn and do the math that the test is assessing, and in the process, they are, in effect, telling students that they’re too dumb to learn — that education isn’t for them. This is a terrible path to set kids on; they are being told that to get through challenges in life, they’ll have to figure out ways to make it seem like they can do things that they’re really incapable of doing. What a sad message, and a wholly unjustified one. This concerns us greatly, as it sets low expectations and damages kids’ self-image; this message is coming from trusted and respected adults who are purportedly experts in the field of education, so students are susceptible to believing this pernicious characterization of their potential. Might these tutors and textbook authors, in fact, be incapable of solving these problems by using math, or might they have decided that even though they know how to solve these problems the right way, they aren’t capable of teaching a student how to do it? Perhaps, but that’s purely on them, not on you. Regardless, they end up sending the message that students shouldn’t bother trying to really learn.
We want students to reject this message regardless of how much authority seems to be behind it. You can learn, and if you apply yourself, you will learn. You’ll have no need for these sketchy tactics, because you’ll be proud to have the SAT give an honest assessment of your abilities.
Stop trying to get the SAT to lie to colleges about your math skills by resorting to these desperate tricks. Learn the math, do the math, and become a better-educated person in the process.
