Differences in children's mathematics knowledge are evident at kindergarten entry, favoring children who have greater access to economic resources. Fostering preschoolers' mathematics learning at home and in classroom settings, through games and other developmentally appropriate activities, is of great interest to educators, early childhood leaders, and policymakers. This cluster randomized trial examined the ef-fects of a naturalistic, game-based mathematics intervention implemented in Head Start classrooms and examined whether including a family math component added value. A total of 573 children (64% His-panic; 60% multilingual) were included from 66 classrooms which were randomly assigned to Classroom Math (CM), Classroom Math + Family Math (CM + FM), or business-as-usual (BAU). Results indicated that the family math component did add value to the classroom-based intervention as CM + FM resulted in a significant positive impact on children's mathematics knowledge relative to BAU, but CM alone did not. For preschoolers age 50 + months, both interventions had significant effects on children's mathemat-ics knowledge relative to BAU, but CM + FM had a stronger effect ( d = .36). The number of math games played was significantly associated with higher mathematics scores and the number of family math mini -books returned had a significant impact on children's spring scores, over and above the number of games played. The CM + FM intervention also had a significant effect on teachers' instructional practice ( d = .79). Adding a family math component to a game-based classroom intervention resulted in positive impacts for preschoolers and seems to be an effective, ecologically valid intervention that fosters early mathematical competencies.(c) 2022 The Authors. Published by Elsevier Inc.This is an open access article under the CC BY-NC-ND license( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Considered a core component of children's foundational cognitive development, early mathematics experiences can support children's long-term academic success. Teachers and families alike share the common goal of wanting children to succeed developmentally, socially, and academically. Given the importance of early mathematics to academic success in all subjects, children need and deserve to build a robust knowledge of early math concepts in their earliest years. In this chapter, we consider the approach of the Young Mathematicians (YM) project at EDC, which for the past ten years, has partnered with families, teachers, and early childhood programs in richly diverse communities with large populations of students of color, linguistically minoritized students, and students living in poverty, to support math learning across home and school environments. We illustrate some of our fun early learning games that engage teachers and families alike and are freely available in multiple languages for anyone to use. We discuss how our close collaboration with families and teachers has informed our approach to equity and report on some of the positive results from our research. Finally, we reflect on ways we can all improve how we are partnering with families and teachers to create equitable and supportive learning communities.