English: Diagram of a 10x10 square grid. The small squares each represent one square millimeter (1 mm2); the entire grid represents one square centimeter (1 cm2). The purpose is to show that even though there are 10 mm in 1 cm, there are 100 mm2 in 1 cm2. More generally, it shows that the conversion factor between units of area is the square of the conversion factor between corresponding units of length. Needs larger text and conversion to .svg format.