I need to float the floor of our new bathroom and there is a 4'' pipe sticking out about 7' for the toilet and I don't know if I am to float the concrete right around it or leave space around it.

i need to float the floor of our new bathroom and there is a 4'' pipe sticking out about 7' for the toilet and i don't know if i am to float the concrete right around it or leave space around it.
That 4 inch diameter pipe is a vent stack most likely. If there is no closet flange visible then that might be the hookup to the toilet so find out what that pipe is for. Usually a vent waste stack combination is only 2 1/2 inch pipe to the roof. (Four inches is not) If you are pouring the slab today I would frame around that pipe and fill later. If that pipe is located where the outside or inside wall frame is, then it is a stack for the second floor waste drain most likely. If no second floor then see choices above. Nm:)

If the 4" pipe's about a foot off the wall it's a safe bet it's a toilet stub-up. If there is no closet wrapper around the pipe,( tap around the pipe to see if it's solid) then cement around it and install a inside closet flange. Good luck, Tom