This qualitative study examines the learning and interaction processes between Latino/a teacher candidates (TCs) and youth during a community service-learning program involving science and math. Knowing and affirming nondominant youth's strengths are essential from funds of knowledge and Third Space perspectives. Participants were 11 TCs and their tutees, 30 youth in first through tenth grades. The study took place in a Texas border colonia, or unincorporated settlement lacking basic services. Data sources were participant observations, youth's interviews and TCs' pre- and final reflections, rapport-building analyses, a focus group, and lesson plans. We found TCs incorporated the youth's funds to develop and implement authentic math and science lessons with them. Implications relate to how community service-learning projects can help TCs' future math and science teaching and can create a Third Space to explore math and science in culturally-relevant ways.