Axes part two

When coordinates are given in pairs, which they often are, we need two number lines, one for each coordinate. These two number lines are called axes. They look like this.

The two axes are perpendicular to each other. The horizontal axis is called the x axis and the vertical axis is called the y axis. Often these are labeled like in the picture below. Some\times arrow heads are added to the axes to show that the lines have the potential to carry on infinitely.

Axes are often drawn on  a grid. The axes below are drawn on a grid. The grid makes it easier to see where points are drawn when they are added to the axes.