A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data
@AP.... Most likely, the data is text, not numeric. Use formulas of the form =ISTEXT(D1) to confirm. The format of the cell does not matter; and looks can be deceiving.
You might be able to correct the problem by selecting a vertical range and using the Text To Columns feature.
If that does not work, there are issues that are difficult for us to "see" in screenshots.
Possibly, the data contains nonbreaking spaces (ASCII 160) or tab characters (ASCII 9). So, entering formulas of the form
=TRIM(SUBSTITUTE(SUBSTITUTE(D1, CHAR(160), CHAR(32)), CHAR(9), CHAR(32)))
in a parallel range, then copy-and-pasting-value back into the original range might correct the problem.
Otherwise, it would be best to upload an example Excel file to a file-sharing website, and post the download URL in a response here. I like box.net/files; others like dropbox.com. You might like onedrive.live.com because it shares the same login as this forum.