# The Metric System

The
**
metric system
**
is a system of measurement based on the
powers of
$10$
. First adopted in France in
$1791$
, the metric system has become widely used in many countries of the world, and is the main system used in science.

The basic metric unit of length is the
**
meter
**
, equal to about
$3.28$
feet. Some smaller and larger units are named as follows:

nanometer(nm) | $\frac{1}{1,000,000,000}$ of a meter |

micrometer(um) | $\frac{1}{1,000,000}$ of a meter |

millimeter(mm) | $\frac{1}{1000}$ of a meter |

centimeter(cm) | $\frac{1}{100}$ of a meter |

decimeter(dm) |
$\frac{1}{10}$ of a meter |

meter(m) |
$1$ meter |

dekameter(dam) |
$10$ meters |

hectometer(hm) |
$100$ meters |

kilometer(km) |
$1000$ meters |

Megameter(Mm) |
$\mathrm{1,000,000}$ meters |

Gigameter(Gm) |
$\mathrm{1,000,000,000}$ meters |

Terameter(Tm) |
$\mathrm{1,000,000,000,000}$ meters |

The same prefixes are used for other units. For example,
$1$
kilogram is equal to
$1000$
**
grams
**
(a unit of mass), and
$1$
centiliter is equal to
$\frac{1}{100}$
of a
**
liter
**
(a unit of volume).

Other metric units include the
**
newton
**
(a unit of force), the
**
pascal
**
(a unit of pressure), the
**
watt
**
(a unit of power), the
**
joule
**
(a unit of energy), and the
**
ampere
**
(a unit of electric current).