**There are 10 centimeters in a decimeter.** In the International System of Units or SI system, the meter is the basic unit of length. Prefixes indicate the multiples and submultiples of units following a decimal pattern.

There are 1,000 millimeters or 100 centimeters in a meter and 1,000 meters in a kilometer. Although these are the most common measurements, there's a different name for every multiple of 10. A picometer is the smallest metric unit of length, and a terameter is the largest. The SI system was introduced in France in 1799, and the definitions of measurements have been updated and refined over the years.