drug calculations

Hi there,

As I've said before I'm moving to Sydney next month. I've been starting to study for my new job in a surgical ward and I was testing my ability in drug calculations. Can't believe how poorly I have done. Shocked and scared at how I've forgotten as most of the drugs I been working with don't required much brain work. I've bought a book to help but was wondering if there was any courses available. I think I would do much better if someone where to explain.