I believe it's around 9 presidents.
all of them except the ones who died in office and the ones who completed their terms without winning a term of their own.
Ten- eight moved up to President when the president died or resigned; one died in office and one resigned before completing his term.
This makes no sense. I am unsure what you mean " completed its full term."
44 presidents but not all of them serve their term
20
six
all of them
Two
Franklin D. Roosevelt was the only President to serve into a fourth term.
5 of the first 10 presidents were re-elected for a second term.
3
3