In a two-story home, it is not necessary to install insulation between the floors except as soundproofing.
With a well-balanced system, the heat transmitting between the floors will aid in the heating of the upper floor, reducing the necessary amount of heating directed by the forced-air system through its ductwork.
Now if you have attic space above the first floor, I would recommend at least an R-40 or the minimum required by your local code. I usually do not recommend spray-in foam in a ceiling condition in an attic unless it is an unventilated hot deck installation.
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