Negative integers appear, when the greater integer is subtracted from the smaller one, for instance: The sign “minus” before 5 shows, that this number is negative.

Series of negative integers continue endlessly: Fractional negative numbers appear, for example, when the greater number is subtracted from the smaller one: Also it is possible to say, that fractional negative numbers appear as a result division of a negative integer by a natural number: Positive numbers in contrast to negative numbers (integers and fractional ones), are the numbers, considered in arithmetic (also integers and fractional ones).

Rational numbers – positive and negative numbers (integers and fractional ones) and zero. The more exact definition of rational numbers, adopted in mathematics, is the following:

A number is called rational, if it may be presented as a vulgar, not a cancelled fraction of the shape: m / n , where m and n are integers.