In prior research and development, the project team developed Woot Math, a web- and app-based mathematics intervention for algebra. With this Phase I funding, the team developed and tested a prototype of Woot Math Polls, an interactive formative assessment platform to facilitate teachers' real-time decision-making while students use Woot Math in the classroom. The prototype allows teachers to create, customize, and remix materials as Open Educational Resources to be shared with other teachers using the intervention.  At the end of Phase I, researchers completed a pilot study with 254 students and nine teachers across grade 8 and 9 classrooms. The research team found that the prototype operated as intended, teachers understood and used the assessment results, and students were engaged during classroom dialogue around the insights shared by Woot Math Polls about their work.