1. We can use various tools to measure mass
( A ) By using beam balance
( B ) By using lever balance
( C ) By using kitchen scale
( D ) By using bathroom scale
2. The standard unit of mass on the metric system is the kilogram (kg) which used to measure the heavy masses, gram (g) and milligram (kg) which used to measure light objects.
For example: A book has a mass of about 1 kilogram (kg)