As a long-time ASVAB tutor, one of the most common questions asked by my students is 'How can I do math questions without a calculator'? That is of course a very reasonable question, and hopefully this article will help you learn the tricks to getting around that little electronic math 'crutch.'
The Math Question Approach
Many of the math questions tested in the ASVAB, both on the Arithmetic Reasoning (AR) section, and the Mathematics Knowledge (MK) section will at first glance appear to require a calculator
In truth, some do, some don't. Some of the questions will be presented in a means that makes you think you are required to perform lengthy conversions and calculations. And many testers wind up wasting quite a bit of time trying to complete these calculations. When in fact, the question is potentially way simpler than it first appears
My first tip to you:
Don't Start Performing Complex Calculations Until You know Exactly What They're Asking For
If the question asks for a general conclusion based on a question that provides nothing but numbers, skip the numbers and answer the heart of the question
But What If Math Is Most Definitely Required?
If the question does indeed ask for a detailed calculation, see if you can guesstimate. Sometimes the answer choices provided will be so different from each other, you will be able to quickly glance at the choices and rule out one or two choices that are so very ridiculously wrong
And What If Math Is Still Required?
Simply where you can. For example, if you are asked a question that requires you to multiply a set of numbers such as 97 x 8. You can revert back to your middle school math training and draw out the standard multiplication formula. This requires writing the number 8 below the 97, followed by multiplying 8 by both 9 and 7. Even if you are fast as doing these calculations, you have probably and needlessly wasted a valuable thirty seconds
Take a look at the answer choices, are they really offering 776 as an answer choice, compared to something like 778 and 780? The answer choices more likely range over a broader scale, for example 89 compared to 9, 778 and 840. In this scenario, when you complete the above calculation, you are looking for a logical ballpark figure, that will give you a close enough answer to rule out the incorrect choices.
The number 97 is pretty close to 100 and can be rounded up quickly in your head. The number 8 is close enough to 10 and can also be rounded. Now that you are faced with 100 times 10, you know your answer is in the range of one thousand. However, two of the choices may be correct at this point, both 778 and 840.
This quick estimation however allows you to rule out the choices that are far below one thousand, leaving you with two choices. If you wish to guess at this point, you have a fifty percent chance of guessing correct, or you can take your estimation a step further
instead of 100 times 10, we can use a more accurate estimation still keeping 97 as 100, but multiplying by 7 instead of 10. This gives the rounded number of 800. In this case, while the answer is still not exact, we can apply one last set of logic. We rounded 97 up, which means our rounded answer will be slightly greater than the actual value. And so comparing 778 and 840, we choose 778 which is lower than the rounded 800.
While the few seconds saved doing this method, perhaps 10 or 20 don't seem like a lot, these seconds add up for each question. And the extra few minutes gained by the end of this section may comprise the difference of a pass or fail, or even the difference between an average or high competitive pass
Source by Leah M Fisch
