All integers are classified as which type of numbers?

Integers are classified as rational numbers because they can be expressed as a fraction where the numerator is an integer and the denominator is a non-zero integer. For example, the integer 3 can be expressed as 3/1, and -2 can be expressed as -2/1. Rational numbers include all integers, fractions, and whole numbers, as long as they can be represented as the ratio of two integers.

This classification is significant because it encompasses not just positive and negative whole numbers, but also zero, making it a more inclusive category. Understanding this helps clarify the broader relationships between different sets of numbers in mathematics.