The purpose of this study was to investigate the differences in parent-child interactions when they played the same numeracy-related game using two formats, a technology-based electronic format and a non-technology traditional board format. It aimed at unpacking the game format effect on parent-child interactions in early home numeracy activities. A mixed-method study with an embedded design was conducted to approach the research questions. In the repeated-measures experiment, 39 parent-preschooler dyads played the same numeracy-related game – The Game of the Goose – using both an electronic format and a board format. The videos of all the play sessions were the data source. Both quantitative and qualitative analyses were conducted. The quantitative analysis was the primary focus. The videos of parent-child play were coded using two pre-determined coding schemes, Parental Scaffolding Behavior and Mathematical Talk. Two repeated-measures multivariate analyses of variance (MANOVA) were conducted respectively for each coding scheme. The qualitative analysis of the 30% selected dyads played a supportive role to further explore the similarities and nuanced differences in parents’ performance of each coded scaffolding behavior across the two formats. The MANOVA for Parental Scaffolding Behaviors showed that the game format had a significant effect on seven of the twelve coded behaviors. The frequencies of Affirmation/Encouragement, Explanation, Inquiry, Re-representation, Modeling, Correction/Disaffirmation, and Physical Control were significantly higher in the board game condition compared in the electronic game condition. The MANOVA for Mathematical Talk revealed an interaction between the game format and the player on Naming Numbers. Both parents and children engaged in more statements about naming numbers in the board condition compared to the electronic condition, but the difference across the two game formats was bigger for parents than for children. In terms of the main effect of game format, the frequencies of Counting, Using Spatial Words and Estimating were significantly higher in the board game condition compared to the electronic game condition. Themes from qualitative analysis revealed parents’ different roles when using the two game formats, as well as the affordances of each format and their influence on parental scaffold behaviors. Interpretations of the results and findings about the game format effect were provided through the lens of sociocultural perspectives and affordances. This study enlarged the understanding of parent-child interaction in early numeracy activities. The findings offered implications for how to help preschoolers develop early numerical skills using different tools and how to design effective learning products for early numeracy using the features of different formats.