Before you close for "homework problem", please note the tags.

Last week, I gave my calculus 1 class the assignment to calculate the $n$-volume of the $n$-sphere. They had finished up talking about finding volume by integrating the area of the cross-sections. I asked them to calculate a formula for $4$ and $5$, and take the limit of the general formula to get 0.

Tomorrow I would like to give them a more geometric idea of why the volume goes to zero. Anyone have any ideas? :)

Comm wiki in case people want to add/modify this a bit.