Tuesday, September 11, 2012

Lil' Help

I need some guidance, help, advice, etc. The first unit in my geometry class was big on vocab to set the pace for the rest of the course. It focused on all of the different types of angles, polygons, and quadrilaterals. We explored each to their fullest, expanding on and making connections to every characteristic possible. In the past I've given an exam with problems and the students have done fine. Recently I started giving this as a quiz instead...
My students have to find all of the angles that I've labeled (36 of them total) in this regular dodecagon. I give them one right angle, but that's it. They need to find everything else on their own. I like this because they need to use the properties we talked about throughout the unit to arrive at the answers. Its a nice, different type of assessment that gets them to apply their knowledge.
I'm having trouble because I don't know how to grade it. Obviously, if they get one angle wrong that is going to through off other angles as well. I can't take points off for every wrong angle because then I'm potentially subtracting points for the same mistake multiple times, which isn't really fair. I need to find a way that assesses them fairly. I've thought about having them write an explanation of how they arrived at their answers, but that would be a ridiculous amount of writing, even if I made a simpler figure with less angles. I've also though about having them list their answers in the order they calculate them so I can try to follow their thought process, but I'm not sure if that would give me the full picture of their understanding. 
Could I evaluate it in some type of standards-based grading system? Are there any other ways that I could use this to assess my students, or do I just simply not grade it but make it a class activity?
Lil' help?

Note: as I type this I'm listening to the Dark Knight Rises soundtrack and I'm now totally pumped to teach for the day, although my lessons may be slightly darker than usual.


  1. I'm no teacher, but maybe you could make them give you not only the angles but also the reason why for each answer. That way, if they get the angle wrong, but they understand the process, they will at least get a point. Also, I would say dont make them give you every angle, just do select ones. (If they understand #20, they will understand #21, etc.) That way, the grade won't be as catastrophic if they accidentally mess up (it would also make the test shorter for their sake, since they would be giving reasons with angles. I would also say, use letters rather than numbers. For me, that would help me not get onfused with the angle value. Again, I'm no teacher. So I could be off base here..