I finally feel like I am getting a hang of the money here; although, it is a little complicated. The Cambodian riel is about 4000r to the dollar. However, the riel is not used exclusively. In fact, Cambodians use USD and Cambodian riel interchangeably. They do not, however, accept US change. So, if something is $3.50 USD you can pay 3 dollars and 2000 riel, or 14,000 riel. If you pay 4 USD you will get 2000 riel back. If you pay 5 USD you might get 1 dollar and 2000 riel back, or you might get 6000 riel back. To make things more complicated, prices can be listed in either riel or USD (never both). Regardless of what it is listed in, you can pay either. Right now I am near the Thai border, where people through baht into the mix. Many of the prices here are listed in baht (I have no idea how many baht to the dollar or to the riel). Here, you can use any of the three currencies interchangeably or together.