Hyphens, En Dashes, Em Dashes

Q. I have a question about physical quantities in a sentence. Does CMOS section 9.13 include weights such as grams and ounces? Example: Berry (1979) did more tests on the 2-gram tablets. Is there a hyphen or not?

A. Chicago style is the same for all physical quantities. Please see the hyphenation chart at 7.85 (number + noun). In nontechnical text, we spell out the number (a two-gram tablet); in technical contexts, we abbreviate the measure and omit the hyphen (a 2 g tablet).