U use a mass or sum of the sort
You would use a tape measure.
You would use Volume.
volume
You would typically use liters or gallons to measure the volume of a hot tub.
The density of a substance is the ratio of its mass to its volume. So, I would measure the mass and volume of a substance to calculate density.
You would use liters (L) to measure the volume of a soda container in the metric system.
liquid volume
This volume can be measured in millilitres.
you would use centimetres to measure the volume for a slice of bread
No, millilitres is a measure of volume not mass. You would use milligrams.
Quarts
millilitres