I have 5 curves on one active data plot and would like to calculate area under the curve for EACH curve and not just the largest curve. I have tried ungrouping the curves and selecting them individually before choosing Integrate from the Calculus menu. I'm not sure what else to try!
Origin can only do the integrate operation on the active dataset. And it will list all the datasets in a graph in the Data menu, so you can choose the data through the menu and then do the integrate operation on it.