How big is the screen you're reading this on? Is it 4 inches—or 10.16 centimeters? The answer depends on where you are geographically. If you're using inches, odds are you're in the U.S. and applying the principles of U.S. customary units—a form of measurement used little elsewhere in the world. In fact, more than 95 percent of the world's population subscribes to the metric system, officially known as Le Système International d'Unités. This is a measurement system built on multiples of 10s, as opposed to the system in place in the United States, which is based on the perhaps nonsensical and out-of-date imperial system.
So what is the reason the U.S. does not use the metric system? Is it time to convert, or is the current system in practice in the United States a better system? Learn more about the evolution of measurement systems throughout the world, and why different parts of the world hold their system so dear.