This session will focus on the progression of content standards and the pathways students may take to become proficient in addition and subtraction. We will engage in a mathematical task involving addition and subtraction, unpack the concepts and skills used in the task, and examine where those concepts and skills fall in the standards as well as in the research on how children develop mathematical understanding. We will examine both learning progressions and learning trajectories focusing on how they each are uniquely helpful in planning for and providing mathematics intervention for students in the early grades.