First, let me say it this way: "If you can use Excel, you can use Calc."
It’s really that simple. Learning to use a spreadsheet — learning the concepts of putting variable data in some cells and putting formulas in other cells to calculate results based on the data — is the hard part.
With one tiny exception… Excel still has one of the Lotus 1-2-3 features that, for some reason, has not been implemented in OpenOffice.
In both OpenOffice and Excel, you can start a formula with an equals sign ("=").
In both OpenOffice and Excel, if you start a cell with a number, but then use any other character (alphabetic or an arithmetic operator like a plus sign), both will treat the cell contents as test — as a label.
But, if you start a cell with a plus sign, they differ. Excel will consider the cell to have a formula. Calc, like Quattro Pro and some others, will consider the cell to be text (a label).
That’s it in a nutshell.
That’s the hardest — and most frustrating — thing that I’ve found in OpenOffice Calc.
If I load an Excel spreadsheet into Calc, it works just fine. The above issue is a keyboard-entry issue. Excel saves “+5” as a formula and Calc reads the formula.
With the arrival of Office 2007 on the scene, you may want to consider OpenOffice instead of one of the expensive copies of Office. After all, it’s powerful, it reads and writes Excel files (as well as Word and PowerPoint files).
And, OpenOffice is free.