One of those mini rulers
METERS!!!The unit of measurement you would use to measure the width of your classroom is meters.
To measure a ladybug, you would typically use millimeters or centimeters, as these units provide a suitable level of precision for small insects. A ladybug usually ranges from about 5 to 10 millimeters in length, making metric units the most appropriate choice for accurate measurement.
Parsecs
Centimetre.
a ruler
Millimetres
You could use either inches or centimeters to measure the width of a sheet of paper.
I would suggest centimeters but lots of people use inches.
15 m
a yard stick
ruler
meters