In this presentation, presenters talk about lessons learned from pioneering progress-monitoring tools, while focusing on one subject, Mathematics. In this process RtI (Response to Intervention) is discussed as a framework while implementing MTSS (Mutli-tier System of Support). Thus, participants will have a chance to discuss the challenges and successes of implementing Growth in national and international settings. Participants will leave will practical tools for problem-solving and resources and ideas on how to set priorities on a classroom level and school level while using RtI/MTSS.