Damn_Underscore posted...
I hate that deci- (decimeter) isn't commonly used, if centimeters are equivalent to inches and meters are equivalent to yards, then decimeters would be equivalent to feet... but no one uses them
And everyone jumps from meters all the way out to kilometers. Nobody ever uses decameters or hectometers. The spell checker in Firefox doesn't even have decameters; it keeps trying to correct it to decimeters.
The metric base unit for area is the are, which is 1 square decameter. A hectare is 1 square hectometer.
You also rarely ever see anything beyond kilometers like megameters or gigameters.