The goal of this SLC Catalyst activity is to create a Center for the Science of Learning in Urban Educating Institutions with a particular focus on school-based learning of mathematics and science. The theme of "mental models" is proposed as the focus in developing a more coherent view of how urban students cope with the increasingly complex demands of academic learning in the important transition years from middle school to college, and to explore more fully how their mental models enhance or deter their academic progress. One of the scientific merits of this work is the aim to bring more coherence to current conceptions of mental models by assembling a team of experts from disciplines in the cognitive, neurocognitive, and socio-cultural sciences who will synthesize current understanding of the idea of mental models into a theoretical framework to guide a series of carefully crafted studies to better document how urban youth learn mathematics and science. The broader impacts of the research on how urban students learn complex academic subjects through their mental representations include the inventions of new learning strategies to enhance urban student's academic progress, especially improving their opportunities to excel at skills needed to succeed in academic studies and to be better prepared to enter colleges and universities. We will utilize digital technology and distance learning strategies to augment classroom-based instructional strategies. Evidence from this research will be used to develop new curriculum materials and teacher education programs to ensure that the work is widely disseminated.