Set file permission to files in subfolders

Question

Using Linux Fedora 20, being in the parent folder, which contains a1, a2, a3, ..., a100 subfolders each with two files in it to which I want to assign a new permission, namely 664. That is I want todo something like chmod 664 -R * but this does not work. Subfolders themselves should not be touched.

Answer 1

find $parent -type f | xargs chmod 664