Cardinal numerals indicate exact number, are being used in counting.
As to their structure, the cardinal numerals from 1 to 12 and 100, 1000, 1,000,000 are simple words (one, two, three, etc., hundred, thousand, million); those from 13 to 19 are derivatives with the suffix -teen (thirteen, fourteen, etc.);
The cardinal numerals indicating tens are formed by means of the suffix -ty (twenty, thirty, etc.).
The numerals from 21 to 29, from 31 to 39, etc. are composite: twenty-two, thirty- five, etc.
NOTE:
- Twenty-Two, Thirty-Five, etc. are spelled with a hyphen.
- In two hundred and twenty-three, four hundred and sixteen, etc. there must be the word and after the word hundred.
Such cardinal numerals as hundred, thousand, million may be used with articles (a hundred, a thousand, a million); they may be substantivized and used in the plural (hundreds, thousands, millions). When used after other numerals they do not take -s (two hundred times, thirty thousand years etc.).
The word million may be used with or without – s (two million, two millions). When the word million is followed by some other cardinal numeral only the first variant is possible: two million five hundred inhabitants.
Functions of cardinal numerals in a sentence
Cardinal numerals are used in the function of subject, predicative, object, adverbial modifier, and attribute (apposition).
…the young man opposite had long since disappeared. Now the other two got out. (Mansfield) (SUBJECT)
Earle Fox was only fifty-four, but he felt timeless and ancient. (Wilson) (PREDICATIVE)
And again she saw them, but not four, more like forty laughing, sneering, jeering… (Mansfield) (OBJECT)
At eight the gang sounded for supper. (Mansfield) (ADVFRBIAL MODIFIER)
Four men in their shirt-sleeves stood grouped together on the garden path. ( Mansfield) (ATTRIBUTE)
And he remembered the holidays they used to have the four of them, with a little girl, Rose, to look after the babies. (Mansfield) (APPOSITION)
Cardinals are sometimes used to denote the place of an object in a series. Cardinals are also used in reading indications: line 23, page 275, Chapter X, No. 49, etc.
…but from the corner of the street until she came to No. 26 she thought of those four flights of stairs. (Mansfield)
Class nouns modified by a numeral in post-position are used without articles.
All he wanted was to be made to care again, but each night he took up his briefcase and walked home to dinner at 117th Street and Riverside Drive, apartment 12D. (Wilson)