"Calculation of Drug Dosages" by Ogden is a great workbook to practice your material. We used this in Pharmacology. We were expected to learn it on our own. Had to pass the test with 90% or better or you failed the entire class. We have to do the same thing in Nursing school as well. This book was very helpful and doing the practice quizzes enabled me to get high scores on each of my tests. My first test was a 96% and I got 100% on the remaining tests. So, get a copy of this book and practice, practice, practice!
If you have trouble with dimensional analysis or how to approach a dosage problem, I highly recommend the book "Math Attack: Strategies for Winning the Pharmacology Math Battle" by Karen Champion. It is GREAT!!! She gives you several different approaches to the same problem and you choose the method that works best for you. It really helped me find the solution style the "clicks" with me. She's also very reassuring and makes you feel like it's not impossible to do well in pharm math
I really liked this book!!
After completing Pharm & passing my math exams, I feel like it'll be no problem in nursing school, since we'll continue with the same book.
Good luck to you!!!!