Generally, chemists measure the mass of things in grams or kilograms (a kilogram is a thousand grams, a milligram is a thousandth of a gram).
(a milligram; is; a thousandth of a gram) Context(a milligram is,List([102, 116))):(a kilogram; is; a thousand grams)
a milligram is,List([102, 116))
a milligram a kilogram
is is
a thousandth of a gram
a thousand grams