Adding up field in Pivot table and Difference between Add Measure and Calculated Field

[jp16]

Hi, i have 2 field in which i want to add up in Pivot Table (A and B)
i discover i can achieve using Calculated Field and also by adding to Data Model, then add Measurement. I Use [A]+[B] in my formula. But i keep getting error. HOwever, when i use =sum([A])+sum([B]), it work. But is it the ideal formula?

And for my case, just a Simple sum up of two field. Is there any difference between using Data Model (add measurment) and Calculated Field? Which method is prefered?

[teylyn]

Hello,

can you please post the DAX formula you are using for the measure? If the measure refers to other measures, please post the dependent formulas, too.