The numbers -1, -2, -3 are negative integers, which are whole numbers less than zero. They are used in various mathematical contexts, such as representing debt or temperatures below freezing. Each number is one unit less than the previous one, indicating a descending order. In mathematics, negative integers can be added, subtracted, multiplied, and divided, following specific rules. For example, adding two negative numbers, like -2 and -3, results in a more negative number, -5. These numbers are essential in understanding concepts like the number line and basic arithmetic operations.