From what I can gather, whole numbers that can be fit in the mantissa of a floating point number are represented exactly:
Can a IEEE 754 real number "cover" all integers within its range?
My question is:
In other words, is there ever a time when floating point 2.0 * 3.0 != 6?
Yes, this falls out from the requirement that the basic operations are correctly rounded. Since the result is exactly representable it is also the correctly rounded result.