100
Spirographs (date unknown. 1970's?)
(media.piefed.ca)
Not much about it, just Spirographs! Nobody is too old to enjoy one. The standard model sold here for $2.99. I never knew they made a motor one!
If I was eph-ewe rich, I would buy a Spirograph for every child in the world. It's gotta be a good thing, to learn that mathematical patterns are cool and fun.
I am only imagining, here, but I'm imagining that the "play" would consist of attempting to use household objects to engineer a supplementary framework of braces and weights to prevent your $6 battery operated plastic toy from skittering off the desk and messing up.