Do you know that you can make “magic” with numbers on the MCAT? In fact, since you are not allowed to use a calculator on the MCAT, understanding some basic principles of math can make certain aspects of the MCAT easier saving you testing time in the long run. All you have to know is that your power comes from being efficient and recognizing patterns.
Even without context, if you see 44.8 or 11.2 on the MCAT, you should think: “I’m dealing with 2 moles (or ½ a mole) of a gas at STP.” Without reading the question, you must recognize that both of those numbers are multiples of 22.4, the molar volume according to Avogadro’s Law. Also, anything times 10 to the power of 23 should bring to mind Avogadro’s number of particles, a multiple or fraction thereof. Now, this does not mean that the answer will always depend on your response! Instead, this exercise shows you how to look for trends and likelihoods that appear in answer choices.
AAMC exams often contain a similar trend. Do the numbers 1.44 and 1.69 ring a bell? They are simply decimal forms of perfect squares (12 squared equals 144; 13 squared equals 169)! A great MCAT math technique is to memorize all the squares between 1 and 15. You have probably known 1 through 10 since elementary school. So, save yourself a future headache and memorize 11 through 15. Then, the next time you see 1.44 on a practice exam or the actual MCAT, you can use your pattern recognition to mentally identify the square root as 1.2.
Do you recall that pi equals 3.14, the square root of 2 is 1.4, and the square root of 3 is 1.7? Do not be surprised if the MCAT asks you to calculate the circumference (2 times pi times r) or area (pi times r squared) of a circle. And get comfortable with estimating the square root of any number. What is the square root of 17? Well, you know it will be between 4 (the square root of 16) and 5 (the square root of 25), but much closer to 4. Do not waste time calculating if there is just one answer that falls between 4 and 4.5.
To minimize stress and maximize time, avoid using decimals until you have no choice. Fractions are much more efficient to use and think about intuitively on the MCAT. Also, get comfortable with using scientific notation for very large and very small numbers. Whenever possible, hang onto variables as they often cancel out or help you in selecting the correct answer.
Feel free to share this information on MCAT Math tricks with other students. If you have any helpful MCAT math tips, please email us at firstname.lastname@example.org. Good luck with your studies!