Grade Scale in openSIS is created to enter letter grades with the actual scores. To create a grade scale go to Grades >> Set up >> Report card Grades. Then create a Grade Scale with a name , maximum scale value & sort order & click on save.
After the grade scale is created, letter grades need to be entered as per requirement. Put the title, Breakoff, Weighted GP value, Unweighted GP value & sort order & then click on save.
The Breakoff fetches the letter grades as per the scores. Here, A=90; when a student gets 90 & above he will be entitled to get an A.
The Weighted GP Value is entered to calculate GPA of the weighted courses (where "Course is weighted" option is on).
The Unweighted GP Value is entered to calculate GPA of the unweighted courses (where "Course is weighted" option is off).
Basically, creating this section would help to get the letter grades on the report card and to calculate GPA while creating Transcript.