* Millimeter (mm): 1 centimeter (cm) is equal to 10 millimeters.

* Micrometer (µm): 1 centimeter is equal to 10,000 micrometers.

* Nanometer (nm): 1 centimeter is equal to 10,000,000 nanometers.

Here are some real-world examples of things that are smaller than a centimeter:

* The thickness of a human hair: About 0.05 - 0.1 mm

* The diameter of a red blood cell: About 7 - 8 µm

* The size of a virus: Typically a few tens of nanometers

Let me know if you'd like more specific examples or explanations!