3 Techniques for Mastering the ASVAB Mathematics Knowledge Subtest

By Angie Papple Johnston

Want to improve your odds of acing the ASVAB Mathematics Knowledge subtest? The following tips will show you how to decipher questions to eliminate wrong answers.

Know what the question is asking

The Mathematics Knowledge subtest presents the questions as straightforward math problems, not word problems, so knowing what the question is asking you to do is relatively easy. However, reading each question carefully, paying particular attention to plus (+) and minus (–) signs (which can really change the answer), is still important. Finally, make sure you do all the calculations needed to produce the correct answer. Check out this example:

Find the value of


(A) 9

(B) 18

(C) 81

(D) 6,561

If you’re in a hurry, you may put 9 down as an answer because you remember that the square root of 81 is 9. Or in a rush, you could multiply 9 (the square root of 81) by 2 instead of squaring it, as the exponent indicates you should. Or you may just multiply 81 by 81 to get 6,561 without remembering that you also need to then find the square root, which gives you the correct answer, Choice (C). So make sure you perform all the operations needed (and that you perform the correct operations) to find the right answer. Here, noticing that you’re both squaring 81 and taking the square root of 812 should make it easy for you to recognize that the answer is actually just 81, without having to work out the multiplication.

Figure out what you’re solving for

Right out of the gate, read the question carefully. Some questions can seem out of your league at first glance, but if you look at them again, a light may go on in your brain. Suppose you get this question:


At first glance, you may think, “Oh, no! Solve for an unknown, s. I don’t remember how to do that!” But if you look at the question again, you may see that you’re not solving for s at all. You’re simply multiplying a fraction. So you take 2/5 times 1/2 and arrive at 2/10, but you should reduce that fraction to get 1/5. The correct answer is Choice (C).

Use the process of elimination

Another method for when you run into questions and draw a total blank is to plug the possible answers into the equation and see which one works. Say the following problem is staring you right in the face:

Solve for x: x – 5 = 32

(A) x = 5

(B) x = 32

(C) x = –32

(D) x = 37

If you’re totally stumped and can’t think of any possible way of approaching this problem, simply plugging in each of the four answers to see which one is correct is your best bet.

Choice (A): 5 – 5 = 32, which you know is wrong

Choice (B): 32 – 5 = 32, which is wrong

Choice (C): –32 – 5 = 32, which is wrong

Choice (D): 37 – 5 = 32, which is correct