What is an SAT Specific Math Strategy?

 

 

Whenever I give SAT math prep advice, the first thing that I always tell my students is to learn as many SAT specific math strategies as possible. So naturally, some of my students will ask me exactly what an SAT specific math strategy is.

These strategies are methods to getting the answers to SAT math problems in ways that are different from the way you were taught in school. Some of these strategies will save time, some will save you from making careless errors, and some will get you the correct answer even when you don't understand the question.

Many of these strategies are not even mathematically correct, but as long as they work there is no reason not to take advantage of them. I know that I may raise a few eyebrows with this statement, but on the SAT you only lose credit if you get the answer wrong – it does not matter if your work is correct.

In the article I am going to give you two sample strategies – one basic and one advanced.

Let us begin with a basic strategy.

Start with choice (C)

In many problems you can get the answer simply by trying each of the answer choices until you find the one that works. Unless you have a specific reason not to, you should always start with choice (C) as your first guess.

The reason for this is simple. Answers are generally given in increasing or decreasing order. So very often if choice (C) fails you can eliminate two of the other choices as well.

As a simple example, consider the following problem:

Three consecutive integers are listed in increasing order. If their sum is 531, what is the second integer in the list?

     (A) 176
     (B) 177
     (C) 178
     (D) 179
     (E) 180

Begin by looking at choice (C). If the second integer is 178, then the first integer is 177 and the third integer is 179. Therefore we get a sum of 177 + 178 + 179 = 534. This is a little too big. So we can eliminate choices (C), (D) and (E).  

We next try choice (B). If the second integer is 177, then the first integer is 176 and the third integer is 178. So the sum is 176 + 177 + 178 = 531. Thus, the answer is choice (B).

Now a more advanced strategy.

Differences of Large Sums

The College Board likes to put seemingly tedious problems on the SAT where it may appear that you have to do a large amount of addition followed by a subtraction.

Most students that attempt to solve this kind of problem directly waste a lot of time and wind up getting the problem wrong anyway.

I am going to illustrate the best way to do this type of problem with an example.

If x denotes the sum of the integers from 1 to 50 inclusive, and y denotes the sum of the integers from 51 to 100 inclusive, what is the value of y – x?

We write out each sum formally and line them up with y above x.

51 + 52 + 53 + … + 100
1 + 2 + 3 + … + 50.

Now subtract term by term.

51 + 52 + 53 + … + 100
1 + 2 + 3 + … + 50
50 + 50 + 50 + … + 50.

Now notice that we are adding 50 to itself 50 times. This is the same as multiplying 50 by 50. So we get 50•50 = 2500..

With a bit of practice this type of problem can become as simple as multiplying 50 times 50 in your calculator. How is that for solving a Level 5 problem in about 5 seconds?.

In summary, if you really want to do well in SAT math it is absolutely critical that you learn as many SAT math strategies as possible. I teach my students 34 key strategies that I feel are particularly important.

The more of these techniques you have at your disposal the less likely you are to waste time, make careless errors, and get tricked during the test, and the more time you will have to check your answers. Each new strategy you learn will take you one step closer to a perfect 800 in SAT math.