By default, students cannot see the gradebook.  To let students see their own grades follow the steps below.

  1. Go to your course
  2. Click Settings (under course title)
  3. In the Appearance section, change Show gradebook to students to "Yes."
  4. Scroll down and click Save and display

screenshot of Appearance section under Edit Settings. The cursor is selecting Yes next to the Show gradebook to students option.