In Spanish, various non-numerical expressions can form complex cardinal numerals in order to (i) denote a range of possible values, and (ii) express uncertainty or vagueness. These include expressions like sesenta y muchos 'sixty and many' and sesenta y pocos 'sixty and few'. The possible numbers that sesenta y muchos denotes are limited to any integer from 66 to 69, maybe less, but not more. Similarly, sesenta y pocos denotes an some integer from 61 to 64, maybe more, but not less. Thus, none of these expressions are simply vague (cf. Krifka 2009); their meaning is more limited. In this paper I present the first analysis of these constructions. The analysis has two main ingredients. First, I argue for a specific compositional account of the syntax/semantics of cardinal numerals in decimal systems. Then I present an extension to these complex cardinals in Spanish, where they are analyzed as determiners introducing subset selection functions over a set of numbers. The approach is flexible enough to account for systems other than the decimal. In addition, it makes clear and empirically testable predictions. If the analysis is on the right track, one would expect to find (i) other complex cardinals of this kind in non-decimal systems, and (ii) other logically plausible combinations of determiners and numerals.