# What was the first system of measurement that was based on units of 10?

##### 1 Answer

You're probably referring to the original metric system, which is now incorporated into the International System of Units (SI).

#### Explanation:

The "metric system" gets its name from the "meter", which was originally defined as the distance from the Equator to the North Pole divided by 10 million (thus the full polar circumference would be 40,000 km). The gram was then defined in terms of the meter and the properties of water (mass of one cubic centimeter of water at the freezing point).

Another early metric unit, the degree Celsius, was taken to be the difference between the boiling point and freezing point of water, divided by 100 -- there are the properties of water again. Perhaps nothing better shows the importance of water in our world.

For a full history see https://en.wikipedia.org/wiki/Metric_system.