How to Approach Math Word Problems on the ASVAB
Word problems are nothing more than a series of expressions that fit into an equation. There will be some on the ASVAB. An equation is a combination of math expressions. The expressions in math word problems are generally stated in English. Your job is to dig out the relevant facts and state them in mathematical terms. You do so by
Understanding the problem
Identifying the information you need
Getting organized isn’t really a step as much as it is a method. You need to be organized throughout the problem-solving process. Working clearly helps you think clearly and ensures you don’t get lost while trying to define and solve the problem.
When using your scratch paper, draw and label your pictures and graphs clearly. And be sure to mark your calculations with the question number. If you go back to your notes and can’t remember what you were thinking about when you drew that picture, you’ll be frustrated and will waste valuable time — and you don’t have any time to waste on the Arithmetic Reasoning subtest.
Understanding the problem
Make sure you read the entire problem, but be careful: Don’t try too hard to understand the problem on the first read-through. That may not make any sense, but bear with me.
Math word problems can be broken down into two parts:
The problem statement: The problem statement isn’t really an object to be understood. It’s simply a source of information, much like a dictionary or telephone book that has information you can look up, as needed, to solve the equation.
The information included in the problem statement is often confusing or disorganized. Sometimes distracters (information that has nothing to do with solving the problem) are mixed in, leading to confusion and making the problem difficult to solve.
The problem question: The problem question is the meat of the matter. Exactly what is the questioner asking you to find? This part of the problem is the one you really need to understand.
Identify the information you need
After you’ve separated the question from the statement, list the facts in a clear, concise list. Identify exactly what the question is asking of you. Figure out what you need but don’t have, and name things. Pick variables (a, x, b, and so on) to stand for the unknowns, clearly labeling these variables with what they stand for.
Be as clear as possible when you identify the information you need. You don’t want to spend five minutes on a word problem solving for x, only to reach the end and forget what x is supposed to stand for.
Pay particular attention to include units of measure, such as feet, miles, inches, pounds, dollars, and so on. One of the fastest ways to mess up on a math word problem is by forgetting the apples-and-oranges rule. You generally can’t perform mathematical operations on different units of measurement. Ten apples plus ten oranges equals 20 pieces of fruit; it does not equal 20 apples, nor does it equal 20 oranges.
Look at the following example:
A carpenter buys 44 feet of wood. If she adds the wood to the 720 inches of wood she already owns, how many feet of wood will she have?
If you add 44 to 720, you’re going to get the wrong answer. Before you can add the numbers, you have to either convert 44 feet of wood to inches (44 · 12 = 528 inches) or convert 720 inches to feet (720 ÷ 12 = 60 feet).
Make sure when you select your answer, it has the correct unit of measurement. Those tricky test writers often give several options with different units in order to make sure you’re paying attention and can correctly identify what unit to use.