ENThe aim of the present study was to investigate longitudinal associations between formal home numeracy activities and children’s arithmetic fluency skills. Children were followed during the transition from the end of kindergarten (T1; Mage = 6.87 years) to the beginning of Grade 1 (T2), and again at the end of the Grade 1 (T3). Participants were Lithuanian children (n = 341) and their parents. At each time point, parents reported the frequency of the formal home numeracy activities they engaged in with their children; the children completed addition and subtraction tasks at the same three time points. Using a cross-lagged analysis, we found that parents adjusted the frequency of their home numeracy activities in response to children’s arithmetic performance. The frequency of home numeracy activities, however, did not predict changes in arithmetic skills. Finally, maternal education was found to be related to children’s arithmetic skills rather than to home numeracy activities. Keywords: home numeracy, numeracy activities, math skills, numeracy, arithmetic fluency. [From the publication]