For a prescription requiring a patient to use two drops in each ear twice a day for nine days, how many milliliters of medication would be needed?

To determine how many milliliters of medication are needed for a prescription that requires two drops in each ear twice a day for nine days, it's essential to calculate the total number of drops needed first.

1. Each day, a patient is instructed to use two drops in each ear, which totals four drops per day (two drops in the left ear and two drops in the right ear).
2. Since the patient must repeat this twice a day, the total drops per day would be four drops multiplied by two, resulting in eight drops daily.
3. Over nine days, the total number of drops required would be eight drops per day multiplied by nine days, equating to 72 drops in total.

To convert drops to milliliters, it's useful to know that commonly one milliliter contains about 20 drops of liquid. Therefore:

• To find the total volume in milliliters, divide the total number of drops (72) by the number of drops per milliliter (around 20):
• 72 drops ÷ 20 drops/mL = 3.6 mL.

Rounding to the nearest practical measurement for pharmacy purposes, 3.6 mL would typically be approximated to 5 mL due