If the courses are on your transcript, you just put in ‘your HS name’ then the school year it was completed.
So for 7th grade classes, we entered ‘2018-2019’; 8th grade ‘2019-2020’.
Hope that makes sense. But I don’t think UT uses the courses and grades anyways since they expect an official transcript from your high school.
From Common App:
Courses & Grades – Other Courses
Use this grid to report your courses exactly as they appear on your transcript.
If any middle school courses appear on your transcript, you do not need to note the middle school’s name. Please use the high school name where you received credit instead.