MCAT Math Advice
1. For example, even with no context whatsoever, if you see 44.8 l or 11.2 l on the MCAT, your Pavlovian response should be: "I'm dealing with 2 moles (or 1/2 a mole) of a gas at STP."
Have you seen these numbers on some AAMC exams: 1.44, 1.69? Do they ring a bell? You should have memorized all squares between 1 and 15. You likely have 1 to 10 stone cold! 11 squared is 121, 12 -> 144, 13 -> 169, 14 -> 196, 15 -> 225. They choose their numbers carefully. The moment you see 1.44 on the MCAT, there is a high likelihood that you would be required to take the square root which gives 1.2. Pattern recognition.
2. A little blast from the past: pi is 3.14, root 2 is 1.4, root 3 is 1.7. Do not be surprised if you need to calculate the perimeter (2 pi r) or area (pi r squared) of a circle. Be comfortable estimating the root of anything! Root 17? Well, the answer must be between 4 and 5 but closer to 4. Check the answers and do not calculate anything if there is only one answer that is between 4 and 4.5.
3. Avoid decimals until you have no choice. Fractions will usually permit you to be more efficient. For huge and tiny numbers, you need to be comfortable with scientific notation. If you can hang on to variables for as long as possible, that's even better. You may be surprised how many times mass m ends up being irrelevant as it happily cancels out!