Test-Taking Strategies

11: Number Problem Strategies

11 Number Problem Strategies You can count on getting better test scores if you attack number problems correctly. It doesn't matter whether the course is math, engineering, or science. It doesn't matter whether it's a standardized test or a teacher-prepared quiz. STRATEGY 1: WORK SYSTEMATICALLY Try to find out in advance whether simple arithmetic errors count and, if they do, how much they count. If knowing the correct method for solving the problem is worth 90 percent, and finding the right answer is worth only 10 percent, don't spend much more than 10 percent of your time on the arithmetic. Don't even double-check your numbers unless you have plenty of time left at the end of the test. On the other hand, if your answer has to be exact, your working habits should be exact, too. Researchers have found out that one out of every five wrong answers on math tests is 61 62 TEST-TAKING STRATEGIES caused by carelessness or mistakes made in working with simple numbers. Here's how to work accurately. Tactic 1: Write carefully Learn to write your numbers carefully so that even under pressure your sevens don't look like ones or fours, and your eights don't look like sixes or zeros. Many students make a European seven (+) to protect against mistakes. Tactic 2: Write in columns For simple arithmetic or elaborate calculations, keep all digits in line; it improves your accuracy, and it helps when you go back to check your work later. There's a reason why your third-grade teacher made you learn to write neat columns for adding and sUbtracting-it makes a difference. Tactic 3: Copy accurately If you have to copy a problem onto work paper, check to make absolutely sure you've copied all the numbers and copied them all correctly. If you have time at the end of the test, check once more. You'd be surprised at how often you can't discover a dumb mistake-such as reading "8" but writing "6"~untll the pressure is off. Tactic 4: Watch for units of measure Before you start working on a problem, deliberately stop and check the units of measurement. This is a major source of wrong answers. If some of the given numbers are not in the proper units of measurement, change them. Be sure that you know and understand what units the answer is supposed to be given in. Number Problem Strategies 63 Tactic 5: Don't play hero If you are allowed to use a calculator, use one. But check your answers anyway. It's as easy to punch in the wrong number as it is to write down the wrong number. The best way to check an answer is to work backward, starting with your answer and finding one of the givens. STRATEGY 2: ORGANIZE YOUR WORK Before you start working on a problem, organize all parts of it systematically and deliberately. Actually write down: • the given numbers; • what you are supposed to find; • all formulas you're going to need, listed in the order in which you expect to use them. If you're taking a classroom test, write all this down on your answer sheet. For a machine-scored test that you're not supposed to mark up, use scrap paper or write lightly on the question sheet and erase when you are finished. On some tests, you'll be able to circle or underline the givens and the find, which means you will just have to jot down the necessary formulas. STRATEGY 3: USE GRAPHICS If you find a particular problem complicated, draw a diagram, graph, sketch-anything that will help you make better sense of the problem. Label the givens on all your diagrams. STRATEGY 4: ESTIMATE If you can, estimate the answer before you start to work 64 TEST-TAKING STRATEGIES out the solution. This is a fast check on whether or not you have used the right method and written the numbers accurately . It's also a check on whether or not you have read your calculator accurately. Example: Given a tank 2.2 feet in diameter and filled to 6.5 feet, what is the maximum weight of the water in the tank? First, jot down the givens as well as the formula (V ='IT r2h) and the weight of water at 4°C. = 62...