Better yet, have your students do it!
An annular eclipse will be passing through Northern California this Sunday. The more populated areas will get a partial eclipse, but that's fun, too.
And a nice opportunity to get photos like this one from Hewitt's Conceptual Physics 11th edition.
So I made it an extra credit opportunity for students who can pull off the photographic feat.
Details on the extra credit opportunity here. That's the student handout I'll give to my students.
UPDATE: Having scoped out potential locations, it struck me that the best places for the tree shadows/sunballs to hit might be a vertical surface (wall) rather than the ground (as depicted in the Hewitt shots). The eclipse peaks late in the afternoon. Shadows are long; the sunballs/crescents may be very distorted on the ground. Just a thought.