I have a workbook with a master spreadsheet and ~100 feeder sheets.

In cell B3 of the master, I want a formula that sums all C3 inputs from the feeder sheets.
I want to drag this formula to the right so cell C3 of the master contains sums of all D3 inputs from the feeder sheets, and
I want to drag the formula down so cell B4 of the master contains the the sums of all C4 inputs from the feeder sheets,
etc

Hard to explain. Hope someone can help.

thebutlerdidit