Greek numerical prefixes
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Numerical prefixes can be used to construct words that refer to a specific quantity of something. For example, in chemistry, carbon dioxide refers to a molecule containing two (di) oxygen atoms. A tetrahedron is a polyhedron with four (tetra) identical faces. A pentagram is a five-pointed star figure.
The following numerical prefixes are from the Greek language:
- 1. mono
- 2. di
- 3. tri
- 4. tetra
- 5. penta
- 6. hexa
- 7. hepta
- 8. octa
- 9. ennea
- 10. deca
- 11. hendeca
- 12. dodeca
- 13. triskaideka
- 20. icosa
- 21. icosakaihena
- 30. triconta
- 40. tetraconta
- 50. pentaconta
- 60. hexaconta
- 70. heptaconta
- 80. octaconta
- 90. enneaconta
- 100. hecta
- 1000. chilia (ch pronounced /k/ in English)
- 10,000. myria
In practice, people often use the Latin prefixes nona and "undeca" for 9 and 11 instead of the Greek ennea and "hendeca". Prefixes above 12 are not commonly used, except 20 in icosahedron, 100 in hectare, and 1000 in the metric system.