We may be able to find where we live on a map, but would we describe it to somebody else? What if they were on the other side of the world and had no idea where our town was? A number line helps with direction, but only left and right, or up and down. This is where a number plane can help us.
A number plane is like having a horizontal number line and a vertical number line! We can describe the position of any point or location using two values, called a pair of coordinates.
A number plane is made up of a horizontal and a vertical axis.
A pair of coordinates describes a point's position away from the origin.
When we plot a pair of coordinates, we draw them on a number plane. For example, to plot the point $\left(2,5\right)$(2,5), we would start at the origin, move $2$2 spaces to the right and $5$5 spaces up.
To name coordinates, we write the horizontal value, then the vertical value that a point is away from the origin. Watch this video to learn more about plotting and naming points on the number plane.
We write the horizontal $x$x-coordinate, then the vertical $y$y-coordinate $\left(x,y\right)$(x,y).
Just like the alphabet, $x$x comes before $y$y.
Now you can have a play with this applet to practise plotting some points.
Plot the point $\left(6,0\right)$(6,0) onto the number plane.
Plot the point $\left(6,3\right)$(6,3) onto the number plane.
What are the coordinates of the plotted point?