Is It or Not? Excursions in Mathematical Definitions


I have been working on a book inspired by Kassia Wedekind’s brilliant daughter Lulu, who argued with her mother last summer about whether an elevator is a vehicle. Lulu was pro; Kassia was con; you may not have considered the matter. I wrote about this late last summer after talking about vehicles with hundreds of people at the Minnesota State Fair.

old rusty bus in the woods
Is this a vehicle?

That led to a second version, which I now share with you in case it might be useful for generating conversations in these difficult times. Is It or Not? Vehicles is pretty much guaranteed to be a good time for all ages.

Is It or Not? Vehicles

The plan is to get a future version of this published, at which point I’ll need to pull this version off the Internet. But that’ll be a while. In the meantime, here’s the spirit of the thing:

  • Download and print as many copies as you like. (Print them back-to-back, and choose “flip on the short side” when you do; then apply a paper cutter in the obvious way, stack and fold and you’ve got a book.)
  • Please share the LINK to this page widely.
  • Please DO NOT share the file. No email attachments; no putting the file on your own blog, etc. Link this page using the URL that is in your browser right now.

Let me know if you have questions, suggestions, or amazing stories of children’s ideas about vehicles and/or definitions.


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