Computes the largest integer value less than or equal to the given value. In other words, round x towards negative infinity.
For example, 2.2, 2.5, and 2.7 all floor to 2.0.
If x is
math.NAN, a NaN will be returned.
If x is integral, ±0, x itself is returned.
Otherwise, the rounded value of x is returned.
FLOAT math.floor(FLOAT x)