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SAT test preparation books sit on a shelf at a Barnes and Noble store June 27, 2002 in New York City. Getty Images

Juniors across the United States will take the preliminary SAT/National Merit Scholarship Qualifying Test, or PSAT/NMSQT, on Wednesday. High schools offer the exam, which includes math, reading and writing, to students every fall. Wednesday is this year's alternate test date.

The PSAT, as it's abbreviated, is important because it gives students an idea of what taking the actual SAT and ACT will be like. It also serves as the qualifying exam for the National Merit Scholarship, a competitive program that pays for its winners to go to college.

Long story short: Even though graduation may seem impossibly far off, you shouldn't blow off the PSAT. Here's how to study for it.

Become familiar with its structure. The PSAT was redesigned last year, so make sure you're looking at the right version, according to Peterson's. The new exam is 2 hours and 45 minutes long, with 47 reading questions, 44 writing questions and 48 math questions. The maximum score you can get is 1520.

Make a study plan. First, as PrepScholar recommends, try a practice test to see what your score might be. Then assess how much you want to improve. If it's under 200 points, plan to study for 40 hours for the actual PSAT. If you want to jump up by 500, though, you should set aside 150 hours.

Check out official practice questions. What better way to study than by consulting the source? The College Board, which administers the PSAT, has sample problems on its website. Want more? Head over to Khan Academy — it has two printable PSATs you can take to get comfortable with your rhythm.

Be careful how you answer. You'll need to take the test in No. 2 pencil. Remember that there are no deductions for questions left blank or answered incorrectly, so you should guess on problems you don't know. Pay special attention to math questions where you have to write your response in a grid — you must bubble in your answer, not just write it at the top, and you can use fractions or decimals.

Get a good night's sleep the night before. If you're reading this hours before taking the PSAT, go to bed. You need to be refreshed and alert, according to McElroy Tutoring. Eat breakfast in the morning, grab a snack on your way out the door and do your best. Like Laurie Hernandez, you got this.