#### Answer

The best unit of measure to express the area of a dollar bill would be square centimeters.

#### Work Step by Step

Clearly, units of square kilometers and units of square meters would be too large to reasonably express the area of a dollar bill. The best unit of measure to express the area of a dollar bill would be square centimeters. A dollar bill is several centimeters long and a few centimeters wide, so square centimeters would be the best choice to express the area of a dollar bill.