Good curriculum doesn’t just teach skills, it builds skills on skills. I’m talking about cumulative skill development—the idea that each new skill builds on previously mastered skills and that earlier material is reused and extended over time. It’s the opposite of “cover it and move on.” In writing, this might look like teaching appositives and then requiring appositives in later lessons while adding new syntactic structures. In math, it might look like teaching learners to unpack word problems—