Rather than using only a worksheet to represent data, you can create a chart to represent the same data. For example, you might want to create a chart and print the chart and worksheet together for a presentation. That way, your audience can easily see trends in a series of values.
If you change any data in the specified chart range, Excel will update the chart accordingly, to reflect the new data in the worksheet. Perhaps you want to track the sales trends of several products with a line chart. Make as many "what if?" projections as you want in the worksheet by increasing and decreasing the values. As you change the values in the worksheet, Excel updates the chart instantly. Excel's charts let you view the sales trends in a picture representation onscreen and the numbers in the worksheet simultaneously, making your sales forecasting more efficient.
Charting is really simple to do. Don't let all the charting commands and options make you think otherwise.