Ok as a student not a pro. I would humbly recommend you to get confident with
drops per minute
and that would really facilitate your progress on solving IV problems
i really like this website, it gives you a clean cut info on basic IV http://home.hiwaay.net/~theholt1/NURS1100/iv-calc.htm
so you can get them down packed and follow on your problems
it seems very confusing but it is about application, applying the information that you have about the drug, on to a process (calculation) in order to get an answer.
if you treat it as a process not a problem, you will get through it way faster, easier, and with less mistakes!!!
remember the basics, and think
if peds: make sure that the order is right, make sure that you have enough, calculate based on weight in kilograms, read your drug book, or the substantial info to make sure that your outcome is within the considered safe dose, and not over the max.