Number terms and quantifiers share a range of linguistic (syntactic, semantic, and pragmatic) properties. On the basis of these similarities, one might expect these 2 classes of linguistic expression to pose similar problems to children acquiring language. We report here the results of an experiment that explicitly compared the acquisition of numerical expressions (two, four) and quantificational (some, all) expressions in younger and older 3-year-olds. Each group showed adult-like preferences for “exact” interpretations when evaluating number terms; however they did not (...) use the corresponding upper bounded interpretation when evaluating the quantifier some. Apparently, children follow different procedures for learning and evaluating numerals and quantifiers. These findings have implications for theories of number representation in child and adult grammars. (shrink)