A number line is a straight line that represents numbers in a visual format. It typically has arrows on both ends, indicating that numbers continue infinitely in both directions. The center of the line usually shows the number 0, with positive numbers extending to the right and negative numbers extending to the left. Each point on the line corresponds to a specific number, making it easy to understand the order and distance between numbers. Number lines are useful for various mathematical concepts, such as addition, subtraction, and fractions. They help students visualize how numbers relate to one another, making it easier to grasp concepts like absolute value and integers. By using a number line, learners can better understand how to perform calculations and solve problems.