I figured out my problem. I had actually created another spreadsheet from a text file (comma delimited). As I stepped through the excel screens, I inadvertently set one of the column formats as text only. When you cut-n-paste this into another spreadsheet, it "looks" like numbers in the cells - but excel treats the cell as text. If you double-click each cell, then hit carriage return, the cell converts to number (actually general).
Sorry for wasting some of your time. I love this usergroup.