The authors developed a classroom experiment on exchange rate determination appropriate for undergraduate courses in macroeconomics and international economics. In the experiment, students represent citizens from different countries and need to obtain currency to purchase goods. By participating in an auction to buy currency, students gain a better understanding of currency markets and exchange rates. The implicit framework for exchange rate determination is one in which prices are perfectly flexible (in the long run) so that purchasing power parity (PPP) prevails. Additional treatments allow students to examine the effects of price changes, tariffs, and nontradable goods on the exchange rate and to explore the possible resulting deviations from PPP. The experiment is suitable for classes of 8 to 50 students and can be run in as short a period as 30 minutes. (Contains 17 notes.)