0 belongs to:
Whole Numbers: 0 is a whole number because it is a non-negative integer.
Integers: 0 is also an integer because it is neither positive nor negative.
Rational Numbers: 0 is a rational number because it can be expressed as the fraction 0/1, and any integer can be expressed as a fraction.
Real Numbers: 0 is a real number because it is a finite, real value on the number line.