Question

Which measurement would be least likely to be written in scientific notation: the thickness of a dog hair, the radius of a period on this page, the ounces in a cup of milk? Explain your reasoning.

Answer 1

None of them NEEDS to be written in scientific notation, IF the best unit is
selected to represent each one ... micrometers for the hair and the period, etc.

For the cup of milk, you specified the unit of measure. Using that unit,
the number is more than 1 and less than 10 , so there's no need at all
for scientific notation.