Kilograms, and the multiples and sub-multiples of the kilogram.
Mass can be measured in -- kilogram, and any of its multiples and sub-multiples -- pound-mass -- slug
There are smaller masses but they need not be submultiples.
minute
The kilogram is the basic metric unit of mass. Its 10-foldmultiples and sub-multiples are also used as appropriate.
Multiple and sub-multiples are used when the range of values is too large to be measured in a single unit.
They divide into a kilogram without remainder.
They are larger quantities of mass.
the meter, along with all of its decade multiples and sub-multiples
"one millionth of ..."
Linear units: Meters and feet and their multiples and sub-multiples, in the SI and Imperial systems respectively.
mass fraction of Substance A = (mass of Sub. A) / (total mass)