How Do I Open Files Without Extensions (made In 1999) and Now Using Mojave?

In 1998, I made a file from Mac’s version of word/pages and they have no file extension, in todays OS High Sierra- by clicking on the name-it shows a terminal exec icon with unix executable. Getting info on it gives no application available to open it. BUT if I manually add.doc to the file then Pages will open it. (BTW I actually downloaded Pages to my MBAir). There are over 30 of these. Is there a quick way to change all at once?
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Karen Frazer