This paper describes an innovative mathematics learning partnership that engages teachers and parents of multilingual children ages 7-10 from schools in underserved communities. At the center of this transformative work is the use of two complementary approaches to advancing equity in education--funds of knowledge and positioning theory. While both theories have been applied in mathematics education, they have not been integrated in a parent-teacher partnership program aimed at enhancing collaboration between multilingual families and teachers. We describe how the theories informed key features of our partnership model, including mathematical tasks and lesson planning activities for parents and teachers. Our research questions focused on how parents and teachers learned about each other's experiences and strengths, and disrupted traditional power differentials between them as they participated in these collaborative activities. Our findings are structured around two in-depth cases that illustrate patterns in our analysis, including features of activities that supported collaborative interactions and co-construction of knowledge. We end with implications for future mathematics education focused partnerships between multilingual families and schools.