Language and culture play a critical role in the teaching of mathematics and this role intensifies when considering the teaching of mathematics in dual language classrooms. This book unpacks lessons learned from socio-cultural theory being applied to research of the teaching of mathematics to Emergent Bilinguals with the end of informing practice. Utilizing a socio-cultural lens, authors present the possibilities and limits of the teaching of mathematics in dual language programs (90/10; 50/50 models). Themes of translanguaging, disciplinary literacy instruction, and culturally responsive instruction are leveraged to test the potential of these constructs to assist Spanish/English Emergent Bilinguals access rigorous mathematics content. Authors also present limits to these models, as often they can overshadow the mathematics learning. We embrace a stance where language and literacy are seen as tools for content area learning and not as ends unto themselves.