Question

order: nph (insulin) 60 units sc q am
supply: insulin vial reads 100 units/ ml
insulin syringe available: 100units/ml
how many units will you give? ______

order: cefprozil (cefzil) 100mg, po, q 12 hours
supply: cefzil 125 mg/5ml
how many mls will you give? ______

order: digoxin (lanoxin) 0.5mcg q am po
supply: digoxin 0.125mcg per tablet
how many tablets will you give? ______

Explanation:

First Sub - Question (Insulin Units)

Step1: Understand the order

The order is for 60 units of NPH insulin. The supply details (100 units/ml vial and 100 units/ml syringe) don't change the number of units ordered. We just need to give the number of units as per the order.
<Expression>Since the order is 60 units, we give 60 units.</Expression>

Step1: Recall the formula for dosage calculation

The formula for calculating the volume of a liquid medication is $Volume=\frac{Desired\ Dose}{Dose\ per\ Unit\ Volume}\times Volume\ per\ Unit$. Here, the desired dose is 100 mg, the dose per unit volume is 125 mg per 5 ml. First, find out how many ml contain 1 mg, then multiply by 100 mg.
<Expression>First, find the volume per mg: $\frac{5\ ml}{125\ mg}=0.04\ ml/mg$</Expression>

Step2: Calculate the volume for 100 mg

Multiply the volume per mg by the desired dose (100 mg). So, $Volume = 0.04\ ml/mg\times100\ mg = 4\ ml$. Or using the formula $\frac{Desired}{Available}\times Volume\ of\ Available$, where Desired = 100 mg, Available = 125 mg, Volume of Available = 5 ml. So, $\frac{100}{125}\times5=\frac{100\times5}{125}=\frac{500}{125} = 4\ ml$.
<Expression>$\frac{100\ mg}{125\ mg}\times5\ ml = 4\ ml$</Expression>

Step1: Recall the formula for tablet dosage

The formula for the number of tablets is $Number\ of\ Tablets=\frac{Desired\ Dose}{Dose\ per\ Tablet}$. The desired dose is 0.5 mcg and the dose per tablet is 0.125 mcg.
<Expression>$Number\ of\ Tablets=\frac{0.5\ mcg}{0.125\ mcg}=4$</Expression>

Answer:

60 units

Second Sub - Question (Cefprozil Volume)