Dynamic Groups for Attendance

Good day,

I've used other BI tools but am relatively new to Power BI.  Here's my challenge.

• I'm working with Education data where my Attendnace fact table stores a record every day a student is absent.
• I'm trying to create dynamic groups that calculate the range that a student falls in.
• These ranges will have to be updated depending on what school year, grade, subject, etc is filtered on.
• The ranges are 0 days, 1-5 days, 6-10 days, 11-20 Days, 20+ Days

I created a lookup table that can be used in the calculation.

Elementary Attendance Days Absent Range

Here's the DAX expression I'm trying to use.  Note that [Elementary Attendance Students] is a distinct count of student numbers.

Days Absent Range = 
VAR AgeRangeDimension = VALUES('D: Student'[OEN])

RETURN
CALCULATE ([Elementary Attendance Students], 
    FILTER ( AgeRangeDimension, 
        COUNTROWS(
            FILTER('Elementary Attendance Days Absent Range', 
                RANKX( ALL   ('D: Student'[OEN] ), 'M: Elementary Attendance'[Days Absent], , DESC ) > 'Elementary Attendance Days Absent Range'[Min Days] 
                && RANKX(ALL ('D: Student'[OEN] ), 'M: Elementary Attendance'[Days Absent], , DESC ) <= 'Elementary Attendance Days Absent Range'[Max Days] ) ) > 0
            )
        )

When I use this column in a dashboard, I just get the value of large number which I beliegve is just summing all of the stduents.  Here are the questions that I'm hoping you can help with.

1. What do I need to do to in the expression above to return the Range column from the lookup table?  Ideally I'd like to see 1 - 5 Days, 6 - 10 Days, etc returned.
2. Should this calculation be a column or measure?
3. Does it matter if the calculation above exits in the fact table or should I create it in a standalone table?

Thanks a lot for your help;

Dave