The unit total should be hidden by default. However you may need to also hide the assessable category total. A savvy student will be able to calculate their totals by combining the results of all their assessments, but LEO is not where students should be getting this information. Final Grades are released through the student system after a moderation and approval process. Marks should not move much from what they have earned in their assessments, however results in gradebook are not the definitive final marks.
It may be useful to hide other items that are formative, not graded or cluttering up the gradebook.
For some activities it will be useful to set a release date for marks. An assignment's grade should be released no more than three weeks after the due date, for example. If a release date is not set, some students may get their results before others - with the results going out as each student's work is being marked.
From Grades > Setup > Categories and items click the 'Edit' next to the gradebook item and then 'Edit settings'. Under the 'Grade item' click 'Show more...' to bring up extra settings.
Please note, with a Turnitin assignment, the marks still may be accessible to students if they go to the assignment directly. Ensure you set a release date in the Turnitin assignment as well, by setting the 'Post Date' in the Turnitin assignment settings.
Please contact the Learning and Teaching Centre for professional development, resources and advice for your learning and teaching needs at ACU.