# Metric System

In the past, every country and in some cases every region were using differnt units of measurement. This diversity made the commercial relations between nations and communities very difficult. In 1792, to resolve these difficulties, the Academy of Sciences in Paris proposed the metric system.

This system has been progressively adopted by all countries, with the exception of Burma, Liberia, and the United States.

In some countries, such as the United Kingdom the metric system coexists with their traditional measurements.

The metric system is a system of units in which the multiple and submultiples of a unit of measurement are related by a multiple or submultiple of 10.

The metric system is used principally for the following magnitudes:

Length

Mass

Capacity

Area

Volume

The units of time are not part of the metric system. They are related between themselves in a multiple or submultiple of 60. Time is a magnitude of the sexagesimal system.

### Complex Measurements

Complex measurements are expressed using different types of units:

3 kg 200 g, 5 km 120 m.

### Simple Measurements

Are expressed using only one type of unit:

3.2 kg, 5.12 m.

### Complex Measurements to Simple Measurements

Convert each of the units into the desired unit.

Convert the following to cm: 12 km 5 dam 42 cm.

### Simple Measurements to Complex Measurements

There are two cases:

1. To convert to larger units, division is used.

5,317 mm

2. To convert to smaller units, multiplication is used.

2.325 km − 2 km = 0.325 · 1,000 = 325

2.325 km= 2 km 325 m