If your students have kept a running chart on their progress of anything, these instructions can be used to show them how to create a line graph in Microsoft Excel. It shows them basics on using formulas to fill in the cells as well.
I had my students keep a chart of their scores on our daily multiplication timed tests. This way, when we graphed the data it was something that was relevant to them. An extension to this activity (which could actually come before doing the Excel graph) could be to graph the data by hand before using the computer and reflecting on which method would be ideal in different situations.