A patient was instructed to drink eight 10-ounce glasses of water daily. How many milliliters is that total?

A patient was instructed to drink eight 10-ounce glasses of water daily. How many milliliters is that total?

• A. 1,200 mL
• B. 2,400 mL
• C. 2,800 mL
• D. 3,000 mL

Answer: (B)

The main idea is converting units from ounces to milliliters using a common medical-math shortcut. Eight times ten ounces gives 80 ounces total. Using the typical conversion used in practice, 1 ounce equals 30 milliliters. So 80 oz × 30 mL/oz = 2,400 mL. If you used the exact conversion (29.57 mL per oz) you’d get about 2,366 mL, which isn’t one of the options, so the problem uses the rounded 30 mL per ounce to produce a clean number. The total daily intake is 2,400 mL (about 2.4 liters).

The main idea is converting units from ounces to milliliters using a common medical-math shortcut. Eight times ten ounces gives 80 ounces total. Using the typical conversion used in practice, 1 ounce equals 30 milliliters. So 80 oz × 30 mL/oz = 2,400 mL. If you used the exact conversion (29.57 mL per oz) you’d get about 2,366 mL, which isn’t one of the options, so the problem uses the rounded 30 mL per ounce to produce a clean number. The total daily intake is 2,400 mL (about 2.4 liters).