Often with GNU Linux you will be asked to change the permissions of a file or folder via the terminal using chmod as below.

For a file:

chmod 644 my_file

or for a folder:

chmod 755 my_folder

However, when you want to check a file or folders permissions in this octal numerical format ls is not going to help you. To view the octal numerical format permissions of a file or folder you can use the command below.

For a file:

stat -c "%a %n" my_file

or for a folder:

stat -c "%a %n" my_folder