Natural numbers are positive numbers starting at 1 and going onward. Since -8.0 is not a positive number, it is not a natural number.
Whole numbers are natural numbers and 0 altogether. -8 is not greater than zero or positive, so it is not a whole number.
A rational number is a number that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q. Since q may be equal to 1, every integer is a rational number. -8.0 can also be written as -8/1, so it is a rational number and an integer, since every integer is a number over 1 and also a rational number.
