If you have decided to take an SAT subject test in math, which exam should you choose -- Math Level 1 or Level 2? The answer is, surprisingly, not straightforward.

Here are four tips that can help you select the math test that best suits your needs.

**[Learn the three questions to ask before taking SAT subject tests.]**

**1. Consider your math abilities: **The College Board, which administers SAT subject tests, recommends you have a minimum of three years of high school math as preparation for either exam.

The two tests primarily differ in the breadth of assessed topics. Math Level 1 contains questions on items like algebraic expressions, coordinate geometry, data analysis and number sequences.

Math Level 2 also addresses these topics, plus items like logarithmic functions and the law of cosines and sines. Both exams require that you answer 50 questions in 60 minutes.

When choosing between the two levels, match your skills to each test. If you do not excel in trigonometry, for instance, consider whether Math Level 2 is truly your best option -- Math Level 1 may be more advantageous.

**[Ask three questions to decide between AP exams, SAT subject tests]**

**2. Investigate school-specific requirements or preferences: **Certain institutions, such as the California Institute of Technology, require prospective students to sit for the Math Level 2 exam. Others may not require math at all or may be satisfied with Math Level 1 or Level 2.

Research the schools on your short list to determine whether they prefer one exam over another as well as how they may use this assessment. Many science, technology, engineering and math -- commonly known as STEM -- programs, for instance, will stipulate that an SAT math subject test must be submitted, but not all will ask for Math Level 2.

The University of North Carolina--Chapel Hill, for instance, requires a math placement score before students can register for introductory chemistry. The school also encourages students who plan to declare a major that involves calculus to register for Math Level 2.

Many schools will consider SAT subject test results during the admissions decision process, but how they interpret the scores can vary greatly. The only way to know with certainty is to read each institution's admissions materials or speak with admissions counselors.

**3. Consider issues of time: **Finally, determine how much time you will need to prepare for each exam. For students with little or no experience with trigonometry, statistics and precalculus, the choice is simple: Math Level 1.

It is almost always inadvisable to self-study these topics to the degree that would be necessary for Math Level 2 -- at least in part because it would involve a serious investment of time.

For students who plan to pursue a degree in a mathematically intense subject -- such as the STEM fields -- you will almost certainly need to take Math Level 2 to be a competitive applicant. Choose a test date that will allow you several weeks for dedicated review.

**[Know three things about SAT subject tests before you study.]**

**4. Review SAT Percentile Rankings:** Be sure to also review the percentile rankings for both exams. In 2016, 20 percent of the students who sat for Math Level 2 received the maximum score of 800. Only 1 percent of students who took Math Level 1 received an 800.

Remember that the score you earn is a measure of how well you did relative to others who took the test. Given that so many individuals received an 800 on Math Level 2 means that a mid-700s result is less impressive than it might be on other exams.

A 750 on the level 2 exam does indicate you have significant mathematical knowledge, you are still only in the top 40 percent of test-takers. In contrast, a 750 on Math Level 1 places you in the top 8 percent.

There are several potential reasons for this difference. For example, students who have completed more advanced math classes in high school may tend toward Math Level 2. The two exams also use different curves.

Before you register, weigh the relative importance of both your target score and its percentile ranking. What are the average scores for Math Level 1 and Level 2 at your top-choice institutions?

If a 750 on Math Level 2 is well above average at your dream school, earning this score may be impressive despite its overall percentile placement. Allow your decision to be guided by both your mathematical abilities and the college-specific data that is available to you.

The difficult choice lies with students who are not required to take Math Level 2 but who possess some experience with the involved topics. Because Math Level 1 covers an easier range of concepts, you could conceivably spend less time studying for that exam and more time on other efforts that will also strengthen your college application.

If you are almost competitive in the Math Level 2 sphere, however, an excellent score could be worth the extra review effort.

It is also possible to take both exams. Accompanying a high score on Math Level 2 with an 800 on Math Level 1 is one way to potentially distinguish your application.

Alternatively, if you took Math Level 2 but did not meet your goal score, you might do better to register for Math Level 1 instead of retaking the level 2 exam.

Brian Witte is a professional SAT tutor with Varsity Tutors. He earned his Bachelor of Science from the University of Washington and holds a Ph.D. from Ohio State University.