How do I allow students to attach files to a Discussion?
You can allow students to attach files to a Discussion by changing the course settings. Settings are available in the Discussions Page or the Course Settings Page.
Discussions Page Settings
Click the Discussions link.
Open Settings Icon
Click the Settings icon to open Discussion settings.
Course Page Settings
You can also change the Discussions permissions in the Course Settings.
In your Course Navigation, click the Settings link.
Edit Course Details
Click the Edit Course Details button.
Click a discussion title.
Verify Students Can Attach Files
In the discussion post, click in the Reply field . The Rich Content Editor  will appear. Verify that students can attach files .