It really depends on if you're mixing aggregates.
Can you please attach a sample workbook so we can replicate?
Here is the workbook that I have with the anonymized data.
The difference is the actual names of the formulas.
Calculated Field A = Shift-Differential Pay Modifier
Calculated Field B = Fringe Pay Modifier
Calculated Field C = WorkStudy Pay Modifier
Calculated Field ABC = Pay Modifier Total
Calculated Field "Formula ABC" = Pay Modifier
WA.POC.MR.1.1.FQ.twbx 52.7 KB
Your sample doesn't match your original summary. So your summary is wrong or your understanding is wrong, or both.
I.e. Pay Modifier Total is not A+B+C, it's only calculating A+B in Tableau.
Then outside of that you're wondering why 'Pay Modified' doesn't equal Pay Modifier Total but the reality is the calculations are very different.
The calculation for 'Pay Modifier' is not the equivalent of the formulas inside of each a+b+c - you're doing conditional logic in this formula on 'class enrolled' which isn't occurring in the pay modifier total field or any of the a, b or c formulas.
Tom - I am going to recheck my formulas here and resubmit the worksheet. Thx for the extra eyes on this. I think that the logic might be off, which is causing the confusion.
Tom - you are correct. The logic on "Pay Modifier Total" was incorrect, thus causing confusion on the end result, which resulted in the assumption in the original post.
A fresh pair of eyes was able to help spot the issue. Thx!