ONe USD gets you 1,237 burundian francs; Bills come in denominations as small as 20 fbu to 10,000 fbu. When you change a hundred dollar bill - known as a Bennie here - you get an impressive stack of bills. Money is only taken out of circulation by some god of naturel destruction. You must produce a perfect unmarked brand new US bill but you will get money sometimes that is too filthy to read the denomination. At that point it becomes a game of hot potato to pass it before it deteriorates;