We don't currently include any information about how learners can be challenged with problems in an ungraded subsection. Teams can add any type of problem to an ungraded subsection, the interaction the learner has with them is exposed on the student progress page.
The LMS does not provide the icon clue in the left nav that there will be something graded, or include an identifier of what type of assignment it is. See LMS.png
The Student Progress page does include the learner's "scores" for these assignments. They are NOT part of the histogram, they appear below it. See progress.png