1. The problem is to understand the classification of numbers based on the given chart. 2. A **rational number** is any number that can be expressed as a fraction $\frac{a}{b}$ where $a$ and $b$ are integers and $b \neq 0$. 3. An **integer** is a whole number that can be positive, negative, or zero, i.e., $\dots, -2, -1, 0, 1, 2, \dots$. 4. A **whole number** is a non-negative integer, i.e., $0, 1, 2, 3, \dots$. 5. An **irrational number** is a number that cannot be expressed as a simple fraction; its decimal form is non-terminating and non-repeating, e.g., $\pi$, $\sqrt{2}$. 6. The chart shows these categories as overlapping sets: integers and whole numbers are subsets of rational numbers, while irrational numbers are separate. 7. Therefore, any number that can be written as a fraction or ratio is a rational number. 8. Integers and whole numbers are special types of rational numbers. 9. Numbers that cannot be expressed as fractions are irrational numbers. 10. This classification helps in understanding the properties and relationships between different types of numbers.