How do I import comma-separated text into Numbers?

Numbers can open .csv files, but not .rtf files.

You can change the extension on the filename to .csv, and open in in Numbers, but changing the extension does not change the contents, and you will see the RTF formatting characters as part of the data.

.csv is a plain text format intended for transfer of data, not formatting. Here's an example, beginning with the original rtf document in Text Edit:

The document was saved as an RTF file, Attempting to open it in Numbers returned a 'cannot open' message.

The extension was changed to .csv, and a second attempt to open it was made, with the result below:

Finally, the document in Textedit was converted to Plain text, then saved with a .csv extension (set in the Save As dialogue—with more recent versions of OS X, you may have to save with .txt, then change the extension in the Finder). The .csv file was then opened into Numbers.

To Insert the .csv file's data into an existing Numbers document:

Open the file as a new Numbers document.

Select and copy the data.

Select (single click) the cell where you want the inserted data to begin, and Paste.

Note that this, like all pastes, will overwrite data in any cells within the range covered by the pasted data.

Regards,

Barry