I purchased the calculator mainly for its currency exchange function. During our last trip to Central America, I noticed that I would either pay too much for items or take too much time converting prices in my head. So, on to Peru with this product and it was one of the most useful things I brought along. I used it for everything from meals to gifts, etc. Shopping and bargaining was so much easier when I can relate the prices to U.S. prices. After saving the currency exchange rate, it would take 2 button presses to convert your value from dollars to ___ or from ___ to dollars.