by Clara Gillan
If you’re preparing for the MCAT, you’ve probably experienced this scenario before: you’re reviewing a practice exam or question set that you’ve completed, and you see a math-based question that you missed. While reading the explanation, you kick yourself, thinking “I totally knew how to do this! I just wasn’t sure where to start!” This sentiment is incredibly common, especially in the Chemical and Physical Foundations section. In fact, knowing where to start is often the most difficult aspect of calculation-heavy problems.
With practice, you can improve your recognition of different types of math-based chemistry and physics questions. But what should you do on Test Day if you see a number-heavy question and you have no clue what’s going on? Below, we’ve listed our top three strategies to help you if you find yourself in this very situation:
1. Use your units! A strong understanding of the relationships between different units can be a lifesaver if you’re stuck or you’ve forgotten a relevant formula. For example, you should be aware that one joule (J) is equivalent to one newton multiplied by one meter (N∙m). If your answer choices are in joules, and the question stem gives you a value in newtons and another in meters, it’s quite possible that you simply need to multiply the two.
2. Mentally note – or physically list – given information. Reading the question stem – especially a long one – might make your head spin, so try summarizing it into a simple list of given values. If you are familiar with your physics and chemistry formulas, this may be enough to jump-start your memory.
Let’s say you are given final velocity, displacement, and acceleration. List these values, then brainstorm equations that you know include them. Here, a promising candidate is the kinematics equation vf2 = vi2 + 2aΔx. See, not too bad!
3. Don’t assume that you need to use all the information given. This is especially true for passage information, which is often extraneous. For best results, familiarize yourself with situations in which certain pieces of information are irrelevant. To return to the example of kinematics, imagine that you are asked to find the time in flight of a skydiver who falls directly out of a moving plane. This skydiver will have the initial horizontal velocity of the plane, but wait: time in flight is not affected by horizontal velocity, but rather by gravitational acceleration and initial vertical velocity. Knowing which pieces of information don’t matter can help nearly as much as identifying those that do.
Finally, if you are still stuck, choose an answer, mark the question, and move on. If you truly have no idea, you’re more likely to miss the question anyway, so there’s no sense wasting valuable time on it. That time is better saved for the easy questions that might appear later in the exam!
With these strategies, we hope that you are one step closer to acing the MCAT. Good luck!