1. Let's start by defining rational numbers. A rational number is any number that can be expressed as the quotient or fraction $\frac{p}{q}$ of two integers, where $p$ and $q$ are integers and $q\neq 0$. 2. This means that every rational number can be written in the form $\frac{p}{q}$, where the numerator $p$ and denominator $q$ are integers, and the denominator is not zero. 3. For example, the number $\frac{3}{4}$ is rational because 3 and 4 are integers and 4 is not zero. 4. Another example is $-\frac{7}{2}$, which is rational because $-7$ and 2 are integers and 2 is not zero. 5. Even integers are rational numbers since they can be expressed as a fraction with denominator 1, for example, $5 = \frac{5}{1}$. 6. Decimal numbers that repeat or terminate are also rational because they can be converted into fractions. For example, $0.75 = \frac{3}{4}$ and $0.333... = \frac{1}{3}$. 7. On the other hand, numbers like $\pi$ or $\sqrt{2}$ cannot be expressed as fractions of integers and are not rational. In summary, rational numbers are those that can be exactly written as a fraction of two integers, including integers themselves and terminating or repeating decimals.