The gradebook will show both a Current Score and a Final Score for your students. These are used to show their scores on both the items they have completed so far, and for the class as a whole.
The Current Score includes all graded items for which the student has a grade. It is used to measure their grade up to the point they are currently at in the course.
The Final Score includes all graded items for a student whether they have a grade entered for the item or not. This means that it includes items that they have not yet worked on or submitted.
It should also be noted that this only applies to the published items in the course since only published items show in the gradebook. For example, if you have only published Unit 1, the Final Score will only be reflective of the items in Unit 1. If all units/modules are published, it will be reflective of the entire course.