- added to a cardinal number to signify one portion of a whole divided into that number of pieces. Creates both nouns and adjectives.
- Ex. "Un doceavo del bizcocho" ("One twelfth of the cake")
Only used for numbers greater than 10. Less common for numbers 1000 and above (use the vigésimo ordinal form which is also signifies portions). When cardinal number ends in -a do not add another (cuarentavo instead of cuarentaavo). The conversion of cien is irregular (centavo)