The formula of Fried is given as:
d = 0.08 a D
Where:
d is the dose for a kid
a is the age of the kid
D is the dose for an adult
We are required to find the dose for an 8-year kid given a medical doctor gives D=1,000 mg of acetaminophen to an adult.
Substitute the given values of a=8 and D=1,000:
d = 0.08 (8) (1,000)
Multiplying:
d = 640 mg