To track the work your students have done independently (not as part of assignments), go to the "Markbook" tab of the corresponding textbook or to the "Students markbook" tab of the group the students belong to. Click on the name of the student whose progress you want to see. If you have a lot of students, you can use the "Search", "Filter" and "Sort by" to find them more easily.
If you are checking the progress of a student whose group has more than one textbook associated to it, you will see a line for each textbook. By clicking on each book, you will see its scores in detail.
Click on the book row to see its scores in detail. You will first see the student's average score and the score for each of the skills.
By scrolling down, you will be able to see all the activities the student has completed. If any of them needs manual marking, you will see a blue pencil icon. To correct the activity, click on the (i) icon to unfold all the information of the activity and then click on "Review".
You can follow the same steps to review your students' answers int he self-correcting activities that already have a score.