If we are getting technical on numbering systems, our numbers are derived from Hindu, not Arabic. I wonder how far we could have advanced (assuming we have) using Roman numbers and without positional notation.
http://www.archimedes-lab.org/numeral.html
Just to keep on the gun topic, Thompson SMG magazines are designated XX, XXX, L, and C. In case you missed it, that is the capacity in Roman numbers, 20, 30, 50, and 100.
Jim