VI. Arithmetic Reasoning: Tips and Tricks
The questions on the Arithmetic Reasoning section of the AFQT use the four basic operations of arithmetic: addition, subtraction, multiplication and division. They ask you to perform those operations, singly or in combination, on whole numbers, fractions, and decimals. Reviewing the basic rules for each operation and lots of practice will both be helpful, but because your time is limited, anything you can do to get the arithmetic done more quickly will improve your score. So, for each operation, weāll look at shortcuts that may speed your work.
A. Addition
Addition is about putting together, combining, and unless youāre working with negative numbers, getting bigger. In the last chapter, we reviewed some of the keywords that signal addition when you meet them in a problem. Now you need to work on the addition itself.
Whole Numbers
Whole numbers include all the numbers you use to countā1, 2, 3, 4, 5, and on and onāas well as 0. Itās easier to describe whole numbers by what they donāt include: fractions, decimals, and negative numbers. When you add whole numbers, you stack them up one under the other with the right side aligned, and add the right-hand columnāthe onesāfirst. If that total has more than one digit, you place the ones digit of the total in the ones column of the answer, and carry the other digits over to the tens column. Repeat moving left to the tens, hundreds, and higher-valued places.
EXAMPLE:
Compatible Numbers
If the numbers youāre adding are small, you may just keep the addition in a line. Called upon to add 4 + 2 + 5, you probably wouldnāt bother to rewrite them one under a...