Up Your Score (30 page)

One thing to look out for when you’re taking the math section is the vocabulary. “What?!” you say. “
More
vocab?” Yup. Sorry.

Expect the SAT to use some technical terms that are intended to throw you off by putting in a term that sounds, well, math-y. Don’t laugh. It actually worked. When the ETS inserted one little term into a math question, the number of students who got it right went from 68 percent to 21 percent. So know your math vocabulary. Do you know what the union of two sets is? What about their intersection? Yes, it sucks to have to learn math vocabulary in addition to your regular vocabulary list, but it will take just a few additional brain cells and a little extra time.

Overall Strategies:
Quick and accurate are the operational words for the math section. If you run out of time, you lose points. And if you do certain things wrong, you lose points. Either way, your grandmother won’t be able to brag about your scores (and you wouldn’t want that, would you?).

Something to bear in mind as you do the math section is that the Serpent’s roar is often worse than his bite. His specialty is what we like to call “shock and awe questions”: problems that look really hard—big equations with fancy variables and exponents—but are actually relatively easy. Faced with an equation that looks like this, 2(n + 5)
²
= 6, for example, many students panic, thinking they have to solve it, when in fact all the question asks is that they simplify the equation. (The correct answer choice is 2n
²
+ 20n + 50 = 6.) So when you see a problem that’s loaded with letters, numbers, and symbols, don’t panic. Realize that it’s probably noisy and harmless, and look at the answer choices
before
solving it.

A Test-Taking Tip:
As on the critical reading section, if you skip a question make a mark in the margin of your test booklet. Put an X next to the questions you don’t think you’ll be able to figure out. Put a ? next to the ones you think you could figure out with more time. If you do your work on a separate sheet, be sure to keep it as neat and organized as you can. Otherwise, you’ll waste time trying to decipher your scribbles.

“Wow!” yelled Jimmy. “I get to use a calculator on the SAT! I’m going to ace this test!” Jimmy assumed he could get by on the math section of the SAT with only a calculator, blew off all his math classes, and didn’t bother to study at all. When test time came, Jimmy realized that there was a lot more to the test than calculators. Jimmy now walks the streets wearing only a garbage bag and bowling shoes.

What is the moral of this sad tale? Don’t put too much faith in your calculator. The ETS says that students who use them do slightly better than those who don’t, but no problem can be completed solely by knowing how to push buttons, and
every math problem can be answered
without
using a calculator. While we’re not going to discourage the use of a calculator, if you’re good at arithmetic, you’ll do fine without it. The trick is knowing when to use it. In addition, make sure you:

1. Know how to use your calculator.

You’re going to feel pretty stupid if halfway through the test you realize you don’t know where the equal sign button is. This is especially true for those of you who have a graphing calculator. Our recommendation: Unless you are totally comfortable using a graphing calculator, bring a regular four-function or scientific calculator instead. The College Board recommends using at least a scientific calculator because of the higher-level math involved. We disagree. Although a graphing calculator can be useful, you could make lots of mistakes if you don’t know the subtleties in entering even a basic problem into the calculator. Even if you’re comfortable with your grapher, you should bring a simpler calculator with you as well to use for basic arithmetic.

Here’s a story: You’re sitting at the testing center. It’s 20 minutes into the first math section and you are finally on the last problem. You read it, realize that you know how to figure it out, and congratulate yourself on your brilliance. You reach for your calculator and . . . it dies. The moral of this story is, always, always, bring a spare calculator or, at least, extra batteries. Janet, a past guest author, brought three calculators. Paranoid? Yes. But she also got an 800 on the math section.

If you find yourself trying to multiply 3,425 by 9,461, you’re probably doing the problem wrong.

2. Know your arithmetic.

The main thing your calculator will be able to help you with is arithmetic: adding, subtracting, multiplying, and dividing. But most of the math problems will not involve complex calculations, and it may be quicker to do them in your head than to use your calculator. For instance, if a problem calls for you to add 21 and 13, your head will move a lot quicker than your fingers to tell you the sum is 34. If you find yourself trying to multiply 3,425 by 9,461, you’re probably doing the problem wrong. Make sure you know the order of the operations—the order in which to plug the numbers into your calculator. First
are all parentheses, then all exponents, then multiplications and divisions, then additions and subtractions. Helpful acronym: PEMDAS. Mnemonic:
P
lease
E
xcuse
M
y
D
ear
A
unt
S
ally. (Sorry, it was made up by math teachers.) Remember it.

Some problems will ask you to decide if something is a factor. Knowing your dividing rules will help a lot. Here’s a chart.

We tried the following problem using these rules and then again using a calculator. We got the answer faster the first time.

What is the
least
positive integer divisible by the numbers 2, 3, 4, and 5?

(A) 30

(B) 40

(C) 60

(D) 90

(E) 120

You can immediately tell that they’re all divisible by 2 and 5 because they end in 0. You can use the 3 rule to cross out (B) and the 4 rule to cross out (A) and (D). That leaves (C) and (E), and since we want the smallest number, (C) is the answer. That wasn’t that bad, was it?

Here’s another arithmetic trick that might come in handy: Check the last digits. If you’re multiplying two numbers together, you can figure out what the last digit of the answer is without multiplying them completely. Multiply the end numbers together and take the last digit of this product.

Example: 23 × 257 = (A) 5,911

(B) 5,312

(C) 4,517

(D) 6,417

(E) 5,118

Without multiplying it out, let’s do a last-digit check: 3 × 7 (the two last numbers) = 21; last digit = 1. Only choice (A) ends in 1, so the answer is (A).

3. Know your squares.

In addition to rules 1 and 2, you should also know your squares and square roots. Questions usually don’t directly ask for squares and square roots, but sometimes you can see shortcuts if you know them. Here’s a table of the squares of numbers 11 to 20. Learn them so that you can save time on your calculations.

If you see one of these squares in a problem, chances are you’ll have to take the square root.

4. Calculators and fractions don’t mix well.

If a problem has fractions in both the question and the answer, don’t use your calculator (unless it’s a graphing calculator). Changing fractions to decimals can be confusing, and there’s no need for it.

5. A word on graphing calculators.

Never use a complicated calculator for the first time on the SAT, but if you have experience with a graphing calculator—if you’ve used it for more than three months—you can save yourself a bundle of time on the math section.

Say you have to determine when two equations are equal to each other. Often the easiest way is to enter each equation into the graphing window of your calculator, then find where the intercept point is. (Some calculators can even directly solve equations. Check yours to see if it has this function.) They can also be programmed. For instance, you can write simple programs to find the area or volume of any geometric shape or solid. Because you have to know the concepts beforehand, the calculator is only useful as a time-saving device—
not
a machine that does the work for you.