  If you throw a needle or stick at random onto a floor ruled with parallel
lines, such as the cracks between floorboards or tiles, from the proportion of
times that the stick lands crossing a crack you can estimate $\pi$; can we get
$e$ as well? Yes, we can. All of these aspects have been discussed before, but
I haven't seen them discussed in this way: that one can estimate both $\pi$ and
$e$ with the same Buffon's needle experiment.
