Students enter classrooms equipped with a rich foundation of skills and knowledge from their everyday experiences. High-quality science education builds on students' wealth of experience in making sense of the world. In science classrooms, "sensemaking" is a collaborative practice that includes students sharing initial ideas with peers and identifying inconsistencies or gaps in their shared understandings about the cause of phenomena or solutions to problems (Odden and Russ 2019). While sensemaking, students are continually drawing on their existing knowledge and integrating it with new information. Therefore, the process of sensemaking in science classrooms includes building or revising explanations for phenomena or iteratively working to solve problems and answer questions. This report discusses why teachers should prioritize student sensemaking, building new knowledge from lived experiences, how curriculum can support student sensemaking, sensemaking with investigations, using texts and media to support sensemaking, using models to support student sensemaking about problems and solutions, and three-dimensional sensemaking. [This report was co-produced by the Carolina Biological Supply Company as part of the Science and Technology Concepts--Middle School (STCMS) program.]