negative and positive numbers
Yes, just look at decimals. Note: integers are a subset of rational numbers.
no, i dont think so
Yes. 1, 2, 3, 4, etc are all both.
Negative numbers are not natural, but there are negative integers. Examples are -1,-2,-3,-4, and so on. These are all integers but none of them is a natural number.
Basically a number without decimals (digits after a decimal point). this can be either positive or negative.