Chem Test

We just took the chemistry test. It couldn't be that bad because I understand most of the stuff...the vocabulary and the main ideas of solutions...but when it comes to measurements and trying to figure out how to solve the equations, I'm lost. I've tried to do most of the stuff like find out molarity and M1V1=M2V2. Doing these equations, I succeeded quite nicely but when it comes to try and figure out how to convert grams to moles, oh my god! Just thinking about this frustrates me because I know that I didn't do well on the test. All in all, I just try to avoid thinking about it in general.