How to convert Km to mtr and mtr to cm and cm to mm

Описание: Converting between kilometers (km), meters (m), centimeters (cm), and millimeters (mm) is straightforward because the metric system is based on powers of 10.
​To convert, you either multiply or divide by a factor of 10, 100, or 1,000.
​📏 Conversion Factors for Metric Length
​The standard relationships between these units are:
​1 kilometer (km) = \text{1,000 meters (m)}
​1 meter (m) = \text{100 centimeters (cm)}
​1 centimeter (cm) = \text{10 millimeters (mm)}