1. ) 1 thru 9 are both natural numbers and whole numbers. 0 is a whole number, but not a natural number.
2.) 6...it is a natural number because it is a counting number and it is whole, it is a whole number and it is an integer as well. It is also rational because it can be turned into a fraction 6/1.
3.) -2 is a rational number because it can be turned into a fraction -2/1, but it is not a whole number because it contains a negative.
4.) That number would be 0