According to Wikipedia (I haven't bothered to check the math), a ternary currency system would maximize the likelihood that a customer would get exact change.

According to Wikipedia (I haven't bothered to check the math), a ternary currency system would maximize the likelihood that a customer would get exact change. http://en.wikipedia.org/wiki/Balanced_ternary http://en.wikipedia.org/wiki/Balanced_ternary So I think we should eliminate the penny; issue three-cent, nine-cent, and twenty-seven-cent coins; and redefine the dollar to equal eighty-one cents.