There are a variety of different synonyms for the phrase "grade by grade" depending on the context in which it's being used. Some possible options include "step by step," "incrementally," "gradually," " gradually," " sequentially," or "stage by stage." Each of these phrases suggests a slow and methodical progression through a process or educational system, with each step building on the previous one in a systematic and organized way. Whether you're talking about educational curricula or professional development initiatives, the idea of moving forward grade by grade or stage by stage is central to achieving success and reaching your ultimate goals.