(e). The cardinal numbers never change their forms for case or number.
Examples.—La du infanoj dividis inter si sep pomojn = The two children divided between themselves seven apples. Unu prenis tri kaj la alia prenis kvar el la pomoj = One took three and the other took four of the apples. Kvin kaj sep faras (or, estas) dek du = 5 and 7 make (are) 12.
(f). Unu is sometimes used in the plural, and unuj then means some. It is used generally in relation with aliaj = others.
Examples.—El ŝiaj multaj infanoj, unuj estas bonaj kaj aliaj malbonaj = Among (out of) her many children, some are good and others bad. Li ekzamenis la pomojn, kaj trovis unujn bonaj kaj aliajn malbonaj = He examined the apples, and found some good and others bad. Note that bonaj and malbonaj are predicative adjectives, and therefore in the nominative (see pars. [36], [108] (b)).
(g). Unu is sometimes used when our indefinite article is employed as a numeral.[14]
Example.—Ĉar ĉiu el ni havas unu vortaron, prenu vian kaj lasu mian = Since we have each a dictionary, take yours and leave mine.
Footnote:
[14] This use of unu is not recommended.
Ordinal Numbers (Numeraloj ordaj).
116. Ordinal numbers, being really adjectives, are, in Esperanto, made such in the usual way by adding A to the cardinals, as:—unua = first, dua = second, tria = third, kvara = fourth, kvina = fifth, sesa = sixth, sepa = seventh, oka = eighth, naŭa = ninth, deka = tenth.