Draw an x-axis and a y-axis on your sheet of graph paper. To do this, use your ruler and pencil to draw a vertical line along the left edge of the paper, and a horizontal line along the bottom edge of the paper.
Give your children a piece of paper with pre-plotted points. For example, you might give them this series:
X: 2, Y:10
X: 5, Y:7
X: 4, Y:9
X:9, Y:8
Find the X-axis point. Then move your finger up the vertical line to the Y-axis point. Draw a filled-in circle, or dot, on that point. Continue in this manner until you have plotted all of your points.
Connect your dots with a ruler by drawing lines from point to point.