Period in integer answers?

[rancom]

Sorry if this is a noobish question among this community, please bear with me as I'm new to the computation world.

I've noticed for some calculations where I'm expecting an integer answer, it will return the expected integer followed by a period. Happened a few times, always ignored. But now that it came up again I'm curious if it means anything. For instance, this just happened to me.

subst((5*x+3)*(x-2)*(3*x+7)*(x+5),x=-6/3)) --> 84.

I ran this command again by up up enter enter. This time it returned 84 without the period.
Then I ran this command again by retyping, and it also returned 84 without the period.

So it seems like this is a random event. Has anyone experienced this and know what triggered this and why?

Edit: I'm using the latest emulator.