You need to know the conversion factor for the two units you are using.
This depends on what unit you are using to measure in. However, area will always be measure in (unit)^2.
division
no, Acres is an Imperial Unit for the measure of area. The metric unit for area is the square meter.
A unit can be a measure of length. It is one-dimensional. A squared unit can be a measure of area. It is two-dimensional. A cubic unit can be a measure of volume. It is three-dimensional.
area, acre
It is the area.
A square unit is a measure of area, a foot is a linear unit. There are no area units in any linear measure.
They are used to measure quantities that are not basic. Length, for example, is a basic unit, but area and volume are not so derived units will be used to measure area and volume.
You could measure a small area.
Square feet is a good unit to measure the area of a room in a house.
you divide or multiply
Cubic kilometres.