round to nearest milligram

Question

When Ibuprofen is given for fever to children 6 months of age up to 2 years, the usual dose is 5 milligrams (mg) per kilogram (kg) of body weight when the fever is under 102.5 degrees Fahrenheit. How much medicine would be usual dose for a 18 month old weighing 22 pounds?

Answer 1

You can use dimensional analysis (unit factor method) to cancel unwanted units keeping the wanted units:

22 lb x 1 kg/2.2 lb x 5 mg/kg = 50 mg