I'd use inches, but centimeters could also work.
meters
The width of a pin would typically be measured in millimeters (mm).
The base unit of length is the metre. You would use metres to measure a park. A Rugby pitch is roughly 100 metres long by 70 metres wide.
I would use meters.
Metres, to measure its length or width, square metres to measure its area.
METERS!!!The unit of measurement you would use to measure the width of your classroom is meters.
Parsecs
Centimetre.
You would use either inches or centimeters.
meters
ruler
meters
Centimeter
Millimetre.
appropriate unit to measure the width of a textbook = ce ntimeters
Identify the SI until you would use the measured the width of your classroom
The answer will depend on what aspect of the calculator you wish to measure: its length, volume, mass, weight, temperature, etc.