In mathematics, a negative and positive number line is a graphical representation of the real numbers (excluding zero), where negative numbers are to the left of zero and positive numbers are to the right. For instance, in depicting temperatures, values below zero (e.g., -10C) are negative, while those above (e.g., +10C) are positive.
This system of organizing numbers has significant practical uses. It facilitates comparisons, additions, and subtractions, offering a simple yet powerful tool for various scientific and mathematical operations. A key historical development was the introduction of negative numbers around the 7th century AD by Indian mathematicians, which revolutionized mathematical calculations.