Since the Earth's gravity pulls on each little piece of mass the same, the mass is easy to figure out from the weight.
(the Earth's gravity; pulls; on each little piece of mass; the same) (the mass; is; easy to figure out from the weight) (the mass; to figure out; from the weight)
the Earth's gravity the mass the mass
pulls is to figure out
on each little piece of mass the same
easy to figure out from the weight
from the weight