This lesson study project emphasizes the critical role of coaches in facilitating the development of collective knowledge around culturally responsive math teaching practices. The project involved teachers and coaches working collaboratively across four grade levels to plan, observe, and reflect on lessons designed to honor student thinking, maintain cognitive demand, and position students as mathematicians. Through the lesson study cycles of studying, planning, teaching, and reflecting, coaches guided teachers in creating culturally relevant math tasks aligned with the theme of nutrition and fitness.

Coaches played a pivotal role in leveraging multilingualism, engaging students in rigorous tasks, creating inclusive environments, and contextualizing math to students' cultural and linguistic backgrounds. Their facilitation was essential in supporting teachers' professional development and ensuring the effective implementation of these strategies.

Vignettes from kindergarten to third grade illustrate how coaches helped teachers maintain cognitive demand, elevate multilingual learners' voices, honor student thinking, and distribute intellectual authority. The project demonstrated that with coaches' support, culturally responsive math teaching can enhance student engagement, confidence, and mathematical understanding, ultimately fostering a sense of belonging for multilingual learners.