I'm attempting to create a monthly report consisting of the sum of
values from about 20 worksheets in a workbook. Here's a rough sketch
of what I'm looking at:

Product Value1 value2 value3
1 1 2 3
2 4 5 6
3 7 8 9
4 10 11 12
5 13 14 15

So let's say there's about 20 sheets that contain these values in
them, and I need to add them all together, to create a summarized
report that looks identical. I'm going crossed-eyed trying to think
of a solution to this. I know there are more archaic ways of doing
this, but I want to make this efficient and quick, perhaps using a
table. I'm in the process of using macros to automate all of the
daily reports that are included in this workbook, and would like to do
the same for the monthly. I would appreciate any help anyone might be
able to offer.