What would change if the unit of measure used to describe the volume of a figure changed from a smaller unit of measure to a larger unit of measure, such as from cubic feet to cubic yards? what would not change?

Fewer numbers of larger units are required to describe the same volume.

a) If the unit of measure changes from a smaller unit to a larger one, the number of units gets smaller

b) The volume doesn't change.

This should be intuitively obvious to anyone with the experience of puting things into containers of any kind. Fewer large containers are required to hold the same amount of stuff that occupies many smaller containers.

Example

54 ft³ = 2 yd³ . . . . the number of units used to describe the volume changes from 54 to 2. The volume is still 93,312 cubic inches. (Note also that both 54 and 2 are smaller than 93,312.)