Introduction: Have you have ever played the game Battleship? If so, you already have a good understanding of how to plot points on a coordinate plane! A coordinate plane is two perpendicular number lines used to graph pairs of numbers. The lines intersect at each line's zero, called the origin. Each line is an axis. 

You need two numbers to locate a point on a coordinate plane. These two numbers are called a coordinate pair. A coordinate pair is written as two numbers inside of parentheses. The first number is the x-coordinate. The x-coordinate tells the distance to travel on the x-axis from the origin. The second number is the y-coordinate. The y-coordinate tells the distance to travel on the y-axis from the origin.