Numeral or number prefixes are prefixes derived from numerals or occasionally other numbers. In English and many other languages, they are used to coin numerous series of words. For example:
- simplex, duplex
- unicycle, bicycle, tricycle
- dyad, triad, tetrad
- biped, quadruped, hexapod
- September, October, November, December
- binary, ternary, octal, decimal, hexadecimal
- septuagenarian, octogenarian
- centipede, millipede
