@peterdrake as one of your former students, and having been through other educational systems (high school in France, MSc in a 3 university program in Switzerland), I think the idea of showing numbers will push towards the standard grading approach. I wouldn't have appreciated the way you are trying to create a memory aid for your teaching, and only looked at the fact that I was being rated numerically.

Ultimately, and this is my understanding (please correct me if I'm wrong in this assumption) for students to get an A means they grok the material, to quote R. Heinlein. There are a few ways to demonstrate the grokking, not all of which are through going above and beyond on given assignments, but maybe side projects they do outside of class where they apply that knowledge.

Another is understanding the applications of the material in a way that they can freely (though like every novice, sometimes ineptly) use the newly gained knowledge to different applications they weren't confronted in the context of learning it. Not entirely sure how that would help, unless you design a self led individual project where they have no choice but to use the content of the course?

I got through with good grades on assignments in my master's because the professors expected to see a grade with every assignment by the TA. But the TAs helped me understand the material without giving me help on the assignments, because I had projects I was working on where I wanted to use that knowledge. I asked about specific help in properly applying the knowledge to the project I was working on, which helped the TA see my motivation, and me to internalize and truly make the knowledge my own. That in turn made it faster for me to understand the material and complete my assignments. In addition to the completed assignments, the TAs also understood that I valued and internalized the material.

I'm just hoping to inspire some other ways of giving feedback, because I don't think numbers are the answer.