Our school also uses Calculate with Confidence and it really helped me, tons of practice questions. Most people are familiar with ratio-proportion, as was I, but I just learned the formula method which is (D/H) x Q, which is Dose Order divided by On Hand then multiply by Quantity. However, if you use this method make sure you know how to convert measurement units as D/H must have the same measurement units, of course. For example Dose order 400 mg po, on Hand is 200 mg/5mL (Q). Start by 400mg/200mg =2 then multiply by 5mL = 10 mL . I hope this help a little and good luck to you.