You've now worked with a [color=#0000ff]horizontal number line [/color]and a [color=#ff0000]vertical number line[/color] (the thermometer). When the two number lines come together, they create a [color=#9900ff][size=150]coordinate plane[/size][/color]. [br][br]The horizontal number line has a specific name on a coordinate plane: [color=#0000ff]x-axis[/color][br]The vertical number line has a specific name on a coordinate plane: [color=#ff0000]y-axis [/color][br][br][size=200]([color=#0000ff]x[/color],[color=#ff0000]y[/color])[/size][br]A coordinate pair tells you where to plot a point on a coordinate plane. The first coordinate tells you [justify][color=#0000ff]how far to move on the x-axis[/color] and the second coordinate tells you [color=#ff0000]how far to move on the y-axis[/color]. [/justify]