5.MD.3 Recognize volume as an attribute of solid figures and understand concepts of volume measurement.
5.MD.3.A A cube with side length 1 unit, called a ?unit cube,? is said to have ?one cubic unit? of volume, and can be used to measure volume.
5.MD.3.B A solid figure which can be packed without gaps or overlaps using n unit cubes is said to have a volume of n cubic units.