On Principle

So I got back a problem set from chem today and I saw that I was docked a point (out of 20). Now I normally don't go arguing with TAs or Professors over points because it's a little degrading and pre-health students get a bad rep for point-mongering anyway. But the reason I got deducted was because I had used significant figures instead of keeping a few numbers past the decimal place. Now this professor has never established any rule on sig figs until a student in class had asked him about it right before our first midterm (after we had turned in our problem sets), to which he responded: "Just put a reasonable number, don't round up too much." Ummm, okay, that's not ambiguous at all.

So I brought up my 1 point with the TA and he looked at it and went "hmmm, thats a good point, ask the professor." So I did. And at first, he was like "however the TAs grade should be fair" and asked what the TA had said. So I told him and I tried to explain myself better.

Professor: So you want one point? That will make you happy?
Me: Well...yeah. But I'm doing it on principle, cause I only made sure to account for significant figures based on the information you gave, I was just being safe.
Professor: *looks more carefully at paper* But even if you did do sig. figures, it should be two numbers.
Me: No, the lowest number you have is 0.04 moles.
Professors: OHH, I see what you did. okay. okay. Alright, I agree with you.
Me: *muhahaha in head*

Yes, I do feel vindicated.