I didn't learn this in kindergarten, but I did learn about Duff's Device in the 7th grade (as it turns out, the Jargon File makes for pretty good reading during

I didn't learn this in kindergarten, but I did learn about Duff's Device in the 7th grade (as it turns out, the Jargon File makes for pretty good reading during boring classes). Never had cause to implement it, though, and never saw this particular hack.