Decimal Handling for Grades

Institutions have specific and intentional policies around handling, calculating, and reporting grades to official transcripts and other systems of record. Blackboard Learn is an important part of this process. Instructors use Blackboard Learn to mark, score, and calculate grades for everyday assessment activities for the purposes of applying grading scales and reporting final grades. Grade reporting policies vary widely, particularly regarding rules about rounding, applying scales, and what happens at scale break-points.

It’s important for administrators and faculty to understand what’s happening in the gradebook when various rules and calculations are applied so that one can adhere to institutional policies. For students, it’s important to have clarity around scores, scales, and grades.

For these reasons, a consistent practice of number handling has been applied throughout Blackboard Learn to address these varied policies and practices while giving users greater transparency into calculations.

Example use cases

Some institutions have a no-rounding policy, particularly at the beginning and end points of applied scales. 

Example: if a “B+” starts at 87.125%, then students are required to have 87.1250% and not 87.1249% in order to achieve a “B+”.

If the scale of “A” starts at 90%, this must be 90.00 and not 89.99 according to many institutions’ policies. When a faculty member views grades as whole numbers, it’s vital for them to understand that the requirement was met and not affected by the rounding behavior of the gradebook software.

Blackboard Learn uses a consistent software library to perform all gradebook calculations to 15 decimal places. To ensure final calculations appear as close to what might be manually re-calculated using the displayed values in the gradebook, a higher level of precision is needed without displaying so much information that it hampers the user experience.

Blackboard Learn's calculation methodologies

To address the varied grade reporting policies and practices, Blackboard Learn takes an approach to meet both simpler policies and the more complex scenarios. Refer to the following list to understand how and why a grade may appear the way it does in multiple areas of Blackboard Learn, including My Grades, Grade Center, and offline grade data. 

These behaviors are expected throughout the application starting with Learn 9.1 Q4 2017 Cumulative Update 1, Q2 2017 Cumulative Update 3, and Q4 2016 Cumulative Update 4.

1. All numbers are shown with at least two decimal places, including whole integers. This is to clearly show that a number is whole and not a result of rounding. 
   • Examples:
     • 100% will display as 100.00%
     • 5 points will display as 5.00 points
2. Calculations that include numbers after the decimal place are shown. However, any trailing zeros beyond the second place are not displayed.
   • Examples:
     • 81% will display at 81.00%
     • 83.3% will display as 83.30%
     • 85.12500% will display as 85.125%
3. Calculations resulting in numbers after the decimal, including repeating numbers, are truncated after the fifth decimal place. This truncation is used only for display and values are never rounded up. Further calculations use the full number up to 15 decimal places. 
   • Examples of truncation:
     • 83.333333333333333…% will display as 83.33333%
     • 75.13792864928…% will display as 75.13792%

       If the above examples are used in additional calculations, the full value (up to 15 decimal places) is used.

Instructors have a greater level of precision and transparency in calculations, so they can choose to round up as appropriate when giving a final grade or in compliance with institutional policies that support rounding up.