There is one-tenth of a centimeter in a millimeter. Centimeters are one one-hundredth of a meter and millimeters are one one-thousandth of a meter; therefore, there are 10 millimeters for every centimeter.
Millimeters and centimeters are part of the metric system, in which all measurements are based upon decimals, and the meter is a basic unit. The prefix milli- is three decimal places to the right of the decimal and centi- is two places to the right of the decimal. Another common metric measurement of distance, length, width and girth, the kilometer, is 1,000 meters since kilo- represents three places to the left of the decimal.