Calculating values from feature service without adding field to service

I am accessing an ArcGIS Online feature service where each day the values in the table are accumulating rather than displaying that day’s data. This is not my feature service so I do not have editing access.
For example, in the example below the value for Day 2 is 5 and the value for Day 3 is 15.

Day 1 10
Day 2 15
Day 3 30

Is there a way to calculate these values in a ArcGIS Online web map or application without writing into the service?