All of you math professors and faculty associates here: when you grade a student who clearly knew what s/he was doing, but whose unfortunate mental arithmetic skills lead him/her to the wrong conclusions, what percentage of the grade do YOU personally think is fair to take off?

Question

anonymous · Answer

Not that I'm bitter or anything. :P

experimentx · Answer

pass percentage and pass mathematics for rest of life

anonymous · Answer

Depends on the type of problem.  If it was, say, a calculus problem, if their calculus was correct, then I would probably give them a 90% of the total points.  If the mistake was more pivotal, then I would give them less points.

anonymous · Answer

But it's in the handbook for ethical bridge building: "Don't miscalculate the stress tensor for the bridge's supports, lest the bridge collapse and kill everyone on it."

So, if it was applied mathematics, would you penalize more harshly? Or, if it were purely theory, would you penalize less harshly?