A country's money can be priced in many ways. The easiest to understand is in terms of an interest rate. For instance, the conventional mortgage rate is currently 4 percent. That's one price of money. But no less important is how money is priced versus something else — a car, gold or even another currency. For instance, a car may cost $25,000. That equation serves to price both the car and the dollar: One car equals $25,000. Alternatively, one dollar equals one twenty-five-thousandth of a car. Thus, we have two measures for the dollar — one, the interest rate, and two, the car.