Working with charts in PowerPoint involves a deep knowledge because hidden beneath the surface are umpteen options that many PowerPoint users are simply not aware of. Through these series of chart tutorials, we have already taught you how you can change chart types or change fills and outlines for chart data series. You also learned how you can play with fonts and other text options of charts, and yet, these ideas are just the tip of the iceberg. One of my pet peeves is how PowerPoint adds so many major units to the Y axis by default.
Change major and minor units of the value axis in PowerPoint 2003 and 2002 for Windows.

