The attendance tool does not connect to the gradebook (and students cannot see it) in My Courses. The "work around" for this is to create grade items in the Grades Tool that are visible to your students. Begin by clicking on the "Grades" tab in the blue navbar, then click "Manage Grades" toward the top left of the page.

Then click on the blue "New" button and select "Item"

Choose the "Numeric" option

Give it a name and how many points it's worth then click "Save and Close" at the bottom. 

Your grade item will appear at the bottom of the grade item list, above the "final calculated grade."

Make a grade item for each class session, each week, or whole term. To grade "Attendance Class 1" click on the "Grades" tab or "Enter Grades" at the top left of the page. Scroll over to "Attendance Class 1" click on the caret next to it and select "Enter Grades" from the menu.