I took mine a few months ago, but if I remember correctly, there weren't any constants I had to memorize. If there were, I'm pretty sure I only had to know R for the PV=nRT equation. There wasn't much math that I had to actually calculate all the way through...it was mostly setting up the equations and then the answer choices were given in parentheses. For example, it was like V= [(.0821)(1.00)(273)]/(1.00) rather than actually making you calculate it.