In this paper we explore the impressive theoretical gap that exists between Sībawayhi’s (d. 177/793?) grammar and that of later grammarians by focusing on the grammar of numerals. We compare Sībawayhi’s Kitāb with al-Mubarrad’s (d. 285/898) Muqtaḍab and Ibn al-Sarrāj’s (d. 316/928) ʾUṣūl fī l-naḥw in order to qualify the different frames in which these three grammarians deal with numerals. While Sībawayhi endeavors to relate numerals to the category of the adjectives which resemble the active participles (al-ṣifāt al-mušabbaha bi-l-fāʿil), al-Mubarrad separates numerals in different categories and analyzes each numeral within its category, and Ibn al-Sarrāj creates an ad hoc category of numerical specifiers that apparently solves all the difficulties. Thus, we identify three directions in which the grammar of numerals evolved after Sībawayhi: i) differentiation as an interpretative tool; ii) a search for local consistencies instead of a global consistency; iii) the appearance of formal semantic categories that make their way into the grammatical analysis.