The Carnival of Mathematics #62 is up today at The Endeavor, and I can tell you right now that I’m totally jealous of the giant Dorito Sierpinski. Now I’m looking forward to seeing Nerd High!

Speaking of Carnivals, though wonder of wonder we’re posting about #62 on the day it appears, there was also a Math Teachers at Play #22 up at math hombre [hey, author John works with a friend of mine! Yup, the math world is getting smaller by the second.]

So that’s the carnival news. And clowns, you ask? Well, I’m thinking that the clowns are the faculty of my department, for coming up with a grading scheme that’s so absurd I’m really tempted to use it in one of my classes next year.

Here’s the idea: Suppose you teach a course and you want to have 3 exams each worth 20% of your grade, homework worth 10%, and a final worth 30%. One way to do this is to set the midterms at 100 points each, the final at 150 points, and homework scaled to 50 points for a total of 500 points in the class.

So far so good, right? The problem with this is that if you offer extra credit you have to be careful not to give too much — you wouldn’t award 10 points for being the first to speak in class, right? (OK, you might, but that would be pretty generous.) So if you want to be able to offer smaller amounts but not have them sound small, you need to have a larger total number of points.

How large? How about 1 trillion points! That ties in nicely to the scale of the national debt, which you can tie together with mathematical literacy and/or an interdisciplinary math/political science activity. Tests are now worth 200 billion points. The final is 300 billion. And now, if a student gives a good answer in class you can off the cuff award them **one million points** of extra credit! The student feels good — who doesn’t like to receive a cool million points in extra credit? — and you don’t even have to bother remembering to enter it in your gradebook. On the other hand, if there are little errors on an exam that you want to point out but don’t necessarily want to penalize (forgetting to write parenthesis, for example, so that 2·(3x+5) is written as 2 · 3x+5 ) you could take off **50 million points**. That’s enough to get anyone’s attention.

I think in some of our classes this would be intimidating, so it’s probably not the best scheme in general. But in other classes, especially the upper level ones, I think our majors would see this as amusing and, perhaps, a help in internalizing the scale of some of these numbers.

Like I said, tempting.

Tags: Carnival of Mathematics, grading

February 6, 2010 at 10:17 pm |

I love the idea of a having a trillion points for the semester! It would be fun to think about how much to take off for a missing “+c” on a Calc exam….

I’ll have to give that a try some time.

February 7, 2010 at 8:19 am |

Somehow I’m reminded of the classic scene from “This is Spinal Tap” — “These go to 11!”

February 7, 2010 at 9:04 am |

When my son asked for an electric guitar for his 8th birthday, I gave him one of my old ones, and bought him a small practice amp to go with it. Not until he was using it did I notice that its volume knob goes to 11.

I’m waiting for a competitor to come out with amps that go to 12.

February 7, 2010 at 9:08 am |

Speaking as one of the clowns mentioned above, I’m happy to see a positive reaction to our grading scheme. It certainly beats the stares we were getting from our students as were laughing hysterically at the thought of taking off a half point for a small mistake, or making sure that no problem was worth a number of points divisible by 10 (this one’s worth 100,000,004 points).

I’m definitely going to try this in the very near future. I currently give 1 homework point to any student who volunteers to solve a problem on the board – how much cooler would it be to offer 10 or even 100 million points for that?