# Metric system

In mathematics, we find physical quantities such as length, mass, temperature, among others. These quantities are associated with certain quantities and a measurement standard called a unit of measurement or simply a unit. A magnitude is any physical property that can be expressed numerically.

A unit is a standardized quantity of a certain physical quantity. By standardized we mean that it takes its value from a pattern. Each physical quantity has a predefined (or basic) unit of measurement.

The metric system or International System of Units (SI) is the system most used at the measurement level. It consists of a set of seven fundamental (or basic) units, which express seven physical quantities; from these other units (known as derivatives) are determined.

## Fundamental Units

 Fundamental quantities Fundamental unit Symbol Length meter m Dough kilogram kg Time second s Electric current intensity amp or ampere A Temperature Kelvin K Amount of substance mole mole Luminous intensity candle cd

## Derived units

 Derived quantities Fundamental unit Symbol Surface square meter m2 Volume cubic meter m3 Speed meter per second m / s Acceleration meter per second squared m / s2 Mass by volume kilogram per cubic meter kg / m3 Angular velocity radian per second rad / s Angular acceleration radian per second squared rad / s2 Frequency hertz Hz Force Newton N Pressure pascal Pa Energy, work, amount of heat joule J Power watt W Amount of electricity electric charge coulomb C Electric potential electromotive force volt V Electric resistance ohm W Electrical capacity farad F Magnetic flux weber Wb Magnetic induction tesla T Inductance Henry H