Is the GMAT topic of number properties driving you crazy? This concept covers things that we often call “basic”—topics that we learned in middle school (or earlier), such as divisibility, factors and multiples, odds and evens, positives and negatives, and so on. I assure you, though, that number properties questions on the GMAT are anything but basic.
I strongly urge you to develop a solid grounding in this topic, particularly because the test writers are so good at disguising what these problems are really testing.
You will need some kind of book or e-book that covers this topic thoroughly, but I have some resources to help you get started.
Start with this article, “Disguising—and Decoding—Quant Problems.” We talk about how the test writers disguise material that you probably do already know, and how we can learn to “decode” the problem or strip away the camouflage.
If you feel good about the concepts discussed in that article, and you are at a higher math level, try out this challenging problem next.
In the article “Patterns in Divisibility Problems,” we examine two GMATPrep problems that share some interesting characteristics. In this article, we discuss some interesting topics related to prime numbers.
Many questions address basic characteristics of numbers, such as whether they are positive or negative, odd or even, integer or fraction/decimal. These can be disguised in various ways; two of the most common are inequalities and absolute values (which we normally associate more with algebra).
Here are two that use inequalities as a disguise for number properties concepts, one in this article and another from this article, as well as a third one that plays around with absolute value. All three of these are generally hiding issues that deal with positive and negative properties of numbers.
And finally here are two more: a number line problem and one dealing with consecutive integers. The former tests positive and negative properties, as well as some others, and the latter covers a less-commonly-tested but still important number properties category.