Pounds are a customary unit. The metric unit is grams.
It is a customary unit.
customary
Fahrenheit is a customary unit
A "gran" is a German measurement, it is neither customary or metric. A "gram" is a metric unit.
Customary.
customary
It is a customary unit.
It is a customary unit.
The pound is NOT a metric unit.
metric.
It is not a metric unit.