Parental engagement in home-based learning activities is linked to children's academic skills. Yet, interventions that try to enhance parental engagement -- sometimes targeted to families with low levels of education -- have small effects. This study aimed to inform supports for families by examining how different types of home-based learning activities influence academic skills during prekindergarten. We created four measures that assessed the frequency with which parents (N = 307) engaged in unconstrained and constrained language/literacy and math activities at home. Unconstrained language activities predicted gains in children's language skills, and unconstrained math activities were associated with gains in math skills. Both associations were larger for families with lower versus higher levels of parental education. Engagement in constrained activities did not predict gains in skills. Implications for practice and research are discussed. [This paper will be published in "Developmental Psychology."]