These numerals express the result of multiplying an amount by a whole number; thus the figure obtained will be doble, triple, cuádruple, etc. As in the case of the cardinals and fractionaries, the multiplicative ones also have quantifying capacity, although it is an "indirect quantification" (NGLE §21.7d).
The series of multiplicative terms, unlike the previous blocks, is, in morphological and conceptual terms, closed.
The categories that develop the multiplicative numerals, according to all the sources consulted, are the ADJECTIVES and SUBSTANTIVES. However, we must point out that in DRAE doble it only presents the adjective label, while triple, cuádruple and following are considered as adjectives that can be used as nouns.
The most common multiplicative forms are those that indicate the multiplication by 2 ―doble―, 3 ―triple―, 4 ―cuádruple―, 5 ―quíntuple― y 6 ―séxtuple―. There are also variants with the suffix -plo, which in current Spanish are less used duplo, triplo, cuádruplo, quíntuplo, séxtuplo.
From 9, they are practically unpublished (except for a hundredfold) and the corresponding cardinal number is used instead, followed by the expression veces mayor or veces más, an analytical formula that also serves to express the idea of multiplication in those cases in which those that there is no specific form of multiplicative; siete veces más, veinte veces mayor.