What is the difference between fraction and rational number...

1 answer

The terms "fraction" and "rational number" are related but have distinct definitions within mathematics.

Fraction:

  • A fraction is a specific way of representing a part of a whole or a ratio between two integers. It is typically written in the form \(\frac{a}{b}\), where \(a\) (the numerator) and \(b\) (the denominator) are integers, and \(b \neq 0\).
  • Fractions can represent proper fractions (where \(a < b\)), improper fractions (where \(a \geq b\)), or mixed numbers (which combine a whole number and a proper fraction).

Rational Number:

  • A rational number is a broader category that includes any number that can be expressed as a fraction \(\frac{p}{q}\), where \(p\) and \(q\) are integers, and \(q \neq 0\).
  • This definition encompasses all integers (since any integer \(n\) can be expressed as \(\frac{n}{1}\)), positive and negative fractions, and zero (which can be expressed as \(\frac{0}{1}\), for example).

Key Differences:

  1. Scope: Every fraction is a rational number, but not every rational number is presented as a fraction in its typical fractional form. For instance, while \(2\) is a rational number (as it can be represented as \(\frac{2}{1}\)), it is not a fraction in the usual sense unless explicitly written in that form.

  2. Representation: Fractions specifically refer to the form \(\frac{a}{b}\) and are usually used to describe parts of a whole or ratios. Rational numbers encompass all numbers that can be expressed in that form.

In summary, while all fractions are rational numbers, the term "rational number" includes a wider variety of values beyond what is typically described by a fraction in its common representation.