That's not exactly how floor() works, sorry DLively.
floor and ceiling are two mathematical functions, see here: http://en.wikipedia.org/wiki/Floor_and_ceiling_functions
Thus the floor() function behaves as follows: "floor(x) is the largest integer not greater than x", which means:
floor(3.41) = 3;
floor(3.99) = 3;
floor(4) = 4;
floor(-1) = -1;
floor(-1.2) = -2;
floor(-1.9) = -2;