I think it probably also depends on the significance of 1 of your local currency -- if you're in Korea, the "feeling" of having 1 won is very different than being in America and having 1 dollar. Or Colombian Pesos, where the currency is in thousand, but they more or less ignore that and put "mil" (thousand) discreetly next to a big number, so that a 2000 peso bill looks like "2" with "mil" in small print.