Length, weight, volume, and more
In the Imperial system (still primarily used by the USA, Liberia, and Myanmar), conversion factors are historically arbitrary. To convert miles to inches, you must memorize that there are exactly 5,280 feet in a mile, and 12 inches in a foot.
The Metric system (SI) was designed during the French Revolution with one simple, universally scalable rule: Everything must be a power of 10.
This makes conversions mathematically effortless. To convert 5 kilometers to centimeters, you don't need a calculator. You just move the decimal point to the right: 5 km = 5,000 meters = 500,000 cm.
Temperature is the one major outlier in standard unit conversion where the math is not just simple multiplication. Because the Fahrenheit and Celsius scales start at different zero-points (freezing vs absolute zero), you have to apply an offset.
To convert Fahrenheit to Celsius, you must first subtract 32 (to align the freezing point of water), and then multiply by exactly 5/9.
Why is the Metric system (SI) considered mathematically superior to the Imperial system?
