What are rational numbers?

Rational numbers are defined as any number that can be expressed as a fraction, where both the numerator and the denominator are integers and the denominator is not zero. This includes whole numbers, integers, and finite or repeating decimal numbers, all of which can be rewritten as fractions. For example, the number 1 can be expressed as 1/1, and 0.75 can be expressed as 3/4. The key characteristic of rational numbers is their ability to be represented as a fraction, which is fundamental to their definition.

The other options provided do not accurately capture the essence of rational numbers. Whole numbers alone do not encompass non-integer fractions, while claiming a number cannot be written as a decimal is incorrect, as many rational numbers can. Finally, stating that numbers have no specific value does not align with the concept of rational numbers, which can indeed be quantified by a fractional expression.