Do contemporary families promote gender-differentiated or egalitarian attitudes and behavior surrounding mathematics? The current study examined mother-child interactions during mathematics homework as a microcosm of contemporary gender socialization. Results revealed individual differences in mothers' treatment of their fifth-grade sons and daughters during mathematics homework interactions, with effects moderated by mothers' gender-role attitudes and mathematics education. Traditional mothers, especially those with greater mathematics education, showed more gender differentiation than egalitarian mothers. Similar individual differences were seen in mothers' and children's attitudes toward mathematics. These findings illustrate the subtlety of gender socialization by showing that mothers' gender-role attitudes, children's gender-role identities, and mothers' education all play important roles in the gender differentiation of children's mathematics attitudes and behavior.