Metric Mastery Practice Test

Understanding metric prefixes and how they change mass values. Milli- means one thousandth, so the mass unit for milligram is the gram divided by 1000. That makes 1 milligram equal to 0.001 grams, and its standard abbreviation is mg. The other prefixes denote different amounts: centigram is 0.01 grams (cg), decigram is 0.1 grams (dg), and the base unit gram is 1 gram (g). So the abbreviation that corresponds to 1 milligram is mg, reflecting the milli- prefix.