Mathematical knowledge at school entry predicts school achievement, and children from low-income families are at risk for low math achievement. The study purpose was to observe low-income parents' numeracy guidance in two contexts, a board game and a number concept assessment, and to compare preschoolers' independent and guided math performances. Eighteen four-year-olds enrolled in Head Start participated with one parent. Although parents employed guidance for a wider range of math activities during the number assessment activity as compared with the board game, the total guidance provided in each context did not differ. In both contexts, children performed at a higher level when guided by a parent as compared with independent math performance. Parental reports of home numeracy practices were positively correlated with children's math abilities but not with observed parent guidance. The findings provide further support for the importance of adult guidance in order to enhance children's opportunities to reinforce known skills and develop new mathematical understandings.