This week’s PSAT/SAT & ACT Math Attack focuses on the values of integers, with particular attention being given to the values of negative integers. If you’re not careful, it’s very easy for a mental error to cause you to miss an otherwise easy question. This week’s question is a great example of a question that, if you’re not paying attention, is easy to miss.

- If [x] is the greatest integer less than or equal to
*x*, what is the value of [-1.6] + [3.4] + [2.7]?- 3
- 4
- 5
- 6
- 7

Before attempting to answer the question, you must understand [x] is an operation:

[x] = (Greatest Integer x)

[x] is representative of the respective values of -1.6, 3.4, and 2.7, and for each of those values [x] must be an integer, which is a positive or negative whole number, and that integer must be less than or equal to the values of -1.6, 3.4, and 2.7.

The first thing you can do is disregard the verbiage “equal to.” Though -1.6, 3.4, and 2.7 are all real numbers, none of them is an integer as they all have decimal points. In light of this, we are now looking for **the integer for each number that is less than but closest to that number in value**.

The respective values of [x] for each of these numbers is

[-1.6] = -2 *Remember: in the case of negative numbers, a smaller number (i.e. a number that is closer to zero) would actually be greater in value, not less than.

[3.4] = 3

[2.7] = 2

After arriving at these numbers it’s a simple matter of plugging them into the equation and solving:

[-1.6] + [3.4] + [2.7] = -2 + 3 + 2

[-1.6] + [3.4] + [2.7] = 3

Thus, the answer is (a).

Miss the last SAT Math Attack? Check it out here! Learn more about the Test Masters PSAT/SAT course here. Go father with Test Masters!