The home learning environment that parents provide for their children is an important context for mathematical development. This study describes the home numeracy environment of Argentinean 5-year-old children of low and high socioeconomic status (SES), specifically in the context of mother-child shared reading of a commercial counting book (Book 1) and a purpose-designed book (Book 2). Results show that the frequency and type of home numerical activities varied depending on SES. However, mothers in both SES groups reported reading to their children regularly, but rarely number books. The results also indicate differences in reading styles and number talk according to SES and book type. On the one hand, low-SES mothers gave more numerical responses than high-SES mothers, while high-SES children solved more utterances correctly than their low-SES peers. On the other hand, variations in number talk by SES were observed only during the reading of Book 2, including the total number of numerical utterances, counting large quantities, and comparing sets of different sizes. The findings contribute to research on the variability of learning activities that adults engage in with their children at home as precursors to numerical development.