Final answer:
The metric unit of measurement for mass is the kilogram (kg), defined as the mass of a platinum-iridium cylinder. It can be divided into smaller units like grams (g) and milligrams (mg), and multiplied into larger units like metric tons.
Step-by-step explanation:
The metric unit of measurement for mass is the kilogram (kg). The kilogram is the standard unit for mass in the SI system. It is defined as the mass of a platinum-iridium cylinder kept at the International Bureau of Weights and Measures near Paris. The kilogram can be divided into smaller units like grams (g) and milligrams (mg), and it can be multiplied into larger units like metric tons.