Organisation Release Grades
By default Students are not shown the grades until you decide to release them to the class but if you wish to automatically Release Grades when students complete a unit, you can enable this feature so when you create new classes this option is automatically enabled.
Enabling this feature will not effect existing classes
Click your name/gravatar, bottom of the left hand pane
Click on the name of your educational organization - under My Organizations, which is about halfway down the screen.
Click the Organization settings tab
Go to the Education Settings section toward the bottom of the page, and enable the feature
The status of this feature can be changed in individual classes if required. See here for more information