Excel - can't delete columns across worksheets

The directions I've found online for deleting columns in multiple worksheets doesn't work. I can select a group of worksheets, all formatted the same, but when I do that the "delete" functions all turn gray except for DELETE WORKSHEETS.  I want to delete, for instance, Columns A-C across six worksheets. How do I do that, please? There's got to be a way!  Thank you in advance