Mathematics achievement at school entry is the strongest predictor for eighth-grade performance, regardless of race, gender, or family socioeconomic status. Yet, California Latine children continue to lack in math proficiency, struggling with concepts such as knowledge of numbers, counting, and spatial and pattern skills development. Existing literature has demonstrated that Family Engagement support children's development. However, Latine parents often feel less comfortable doing math themselves and in participating in their children's math learning. This interpretive phenomenology research study was designed to uncover participants' cultural repertoires and learning experiences to explore how Latine families perceived and engaged in co-design workshops to develop a mathematics activity for their 3-5 years old children. This study collected data from (a) semi-structured interviews and (b) co-design workshops (including co-design workshop recordings, transcriptions, photos and screenshots). Thematic analysis identified the key findings that emerged from the semi-structured interviews are (a) traditional education virtues, (b) familismo, (c) role of language, (d) ecological environment, (e) views on knowledge, (f) interest-driven learning, (g) identity formation related to (math) learning. Further, building upon existing frameworks, this study's results and analysis suggest that through co-design approaches, Latina mothers engaged in (h) teamwork and collaboration, (i) sense-making, (j) intrapersonal openness, and (k) conscientiousness in the co-design and co-construction of a mathematics activity for their children. In centering Latina mothers as designers and users of their own mathematics learning experience, it positioned them as experts in their own and their children's learning and allowed for the co-design and co-creation of a meaningful learning math experience. Co-design approaches may be helpful to engage marginalized groups, such as the Latina mothers in this study, to achieve successful family engagement outcomes. Co-design approaches herald a different way of engaging Latine families as an alternative to standard family engagement interventions. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]