Using Calculators on the SAT

By Mark Zegarelli

Part of SAT Math For Dummies Cheat Sheet

When taking the SAT, you’re allowed to use a calculator. Calculators can save a lot of time on the SAT if you save them for when you can’t quickly and easily do a calculation in your head. The more complicated a single calculation is, the more likely you are to enter it incorrectly, so if possible, break down complicated calculations into several steps before keying them in.

Make sure you know how to use your calculator to do the following (check out your calculator’s manual or reference card if you’re having trouble):

  • Perform basic numerical operations. Make sure you feel very comfortable doing basic addition, subtraction, multiplication, and division on your specific calculator.

  • Work with decimals. Locate the decimal point key and make sure you know how to use it.

  • Make numbers negative. On many calculators, the key for negating a number is distinct from the key for subtraction.

  • Find a square root. Locate the square root key and make sure you can find square roots.

  • Square a number. Your calculator probably has a key that looks something like x2, used for squaring a number.

  • Raise a number to the power of another number. Your calculator may have a key that looks something like ^ or xy, which allows you to raise a number to the power of another number.

Following are a few other skills that are likely to come in handy:

  • Fractions: Some calculators allow you to perform operations on fractions and specify that the answer be provided as a fraction. This feature can be useful when a multiple-choice question provides fractional answers.

  • Parentheses: Knowing how to group numbers using parentheses allows you to tell the calculator which operations to do first.

  • Higher-order roots (radicals): Some calculators have a key that allows you to find higher-order radicals such as cube roots, fourth roots, and so on. But many calculators require you to calculate higher-order roots as powers of a fraction. Find out how to do this so you can repeat it on the test if needed.

  • Solving equations: The equations that you need to solve on the SAT aren’t designed to be too complex, but if your calculator allows you to solve an equation for a variable, you may find this feature useful.

  • Graphing functions: In some cases, you may find graphing a function helpful for answering a question. For example, graphing may save time solving a quadratic equation: Just graph the function and zoom in on the zeros to find x.

  • Using input-output tables: Graphing calculators usually have a feature allowing you to make an input-output table for a function. This feature may come in handy on the SAT, so check it out.