I put together this warm up for them yesterday to continue practicing:
I'm embarrassed to say, I didn't realize what good functions I had chosen until the kids started working on it.
"Can there be more than one pair?"
"Ummmm...yes, but you should match up the functions so that you use each exactly once."
The puzzle was that, for example, 2x+3 could be the derivative of x^2+3x-7...or it could be the antiderivative of 2 (not that we're using that jargon yet...). Similarly, 5 could be the derivative of 5x, or it could be the antiderivative of 0.
Again, I would love to say I planned all that in advance, but it was a total accident. However, I'm not sure I've ever seen kids this into a warm up. They asked for more like this...