Identify the desired dose: The doctor has ordered 40 mg of atorvastatin. Identify the available tablet strength: Each tablet contains 10 mg of atorvastatin. Set up the calculation: We need to find out how many tablets are needed to administer 40 mg of the medication. We can use the following formula: (Desired dose) / (Tablet strength) = Number of tablets Plug in the values and calculate: (40 mg) / (10 mg/tablet) = 4 tablets