Summing columns of variable range in multiple tabs and collating them into a master sheet

Good Morning,

I am a VBA newbie, so please bear with me if this is painfully simple.

I have used VBA to mass import CSV files into separate tabs within a single work book. The number of files imported, and therefore tabs, is variable, but typically between 10 and 25. What I am trying to do, and failing horrifically, is sum the same two columns (of variable range, so using a loop until there is nothing in the previous column?) in each tab individually, and then collate the output of the sum in separate columns in a master tab.

Any help would be greatly appreciated.

Regards,
Clown

Can you attach a sample file? Show which two columns you want to sum (perhaps maybe two or three sheets), and how you want the results to be entered in the master tab.

Please find attached an example of two exported CSVs and the desired output.

Many thanks,

Clown