There is an enormous deficit in students’ understanding of fractions in the United States. Fifth grade fraction knowledge predicts high school math performance, even when controlling for working memory, whole number knowledge, IQ, reading ability, and demographic factors (Siegler et al., 2012). Therefore, addressing this deficit is a particularly important area for early intervention. With this Fast-Track grant, Deep Fractions Learning , we propose to transform the way in which students learn core math curriculum so that materials are more interactive and engaging, promote deeper learning of content, and are aligned with the Common Core. More specifically, we will develop and evaluate a digital curriculum for grades 3-5 covering the fractions domain that combines games, collaboration, and an inquiry approach. We propose to develop an innovative technology infrastructure that will integrate Teachley learning games, Success for All’s (SFA) cooperative learning framework, and rigorous lesson content. We will integrate research into the design process and work with Johns Hopkins University to evaluate the efficacy of the intervention. Outcomes. The intervention will encourage four direct outcomes for students, namely improved: 1) conceptual understanding of fractions, 2) procedural fluency with fractions operations, 3) mathematical justification, and 4) motivation. First, the curriculum will build both conceptual understanding and procedural fluency, providing strong visual models within engaging games that motivate students to practice. The collaborative learning model and inquiry approach will improve students’ mathematical justification. Finally, we encourage these outcomes within a motivational support structure designed to foster engagement and self-efficacy. Improving students’ academic outcomes and self-efficacy in the area of fractions during elementary school will promote later success in high school mathematics. Since each additional math class students complete in high school more than doubles the odds of college completion (Adelman, 2006), the intervention has the potential to make a real difference in whether students achieve sustainable careers versus being stuck in low-wage jobs.