That's a pretty good point, actually. I had nine groups rolling dice. I love you guys, because instead of writing out the groups longhand like I had to do for my prof and my classroom teacher, I can tell you there was one group each rolling:
1d6
2d6
3d6
1d8
2d8
3d8
1d10
2d10
3d10
I wanted them to see that the 1dx groups got a random distribution, but that the 2dx and 3dx groups got bell curves. Unfortunately, I only got one beautiful bell curve out of the bunch--the 2d6 group came out exactly right. I want to find a way to convince them that on average, most curves for multiple dx will look like the 2d6 group's curve.
Daniel