You probably want something like
or (if "
textfiles is my directory" means you're inside the directory):
Note these commands don't restrict themselves to regular files. Directories, symlinks, named pipes and other entries may match. In broad Unix context all these are "files" and such matching is done with respect to their names only. To tell regular files apart, you need another tool like
I'm surprised any guide advised you
ls [0-9] textfiles as it makes little sense in the context of your question.
*[0-9]* refer to
man 7 glob or e.g. this article, Standard Wildcards (globbing patterns) section. It's worth noticing in the above cases it's the shell (not
ls!) that expands the given pattern.