The metric system is a simple measurement system used by every single country in the world -- except for the United States and a few African countries including Liberia. The United States should switch to this system for many reasons, some of which are big and some of which are small. Here are three:
1. TRADE. Trade would be much smoother if there was a universal system of measuring liquids and foods. Actually, there already is, but the U.S. is stubborn enough to reject it.
2. TOURISM. Tens of millions of tourists visit the U.S. every year only to be confused by miles, yards, feet, and inches. Adopting the metric system would make it much easier for tourists in many situations.
3. EASE OF USE. The metric system is much easier to use than the Imperial system that the U.S. currently uses.