I have a list of various scrap materials inventory by weight (kg) that is reported out weekly. Here's an example:
MATERIAL CODE MATERIAL TYPE 2-Jan-17 9-Jan-17 16-Jan-17 23-Jan-17 30-Jan-17 Feb-06-17 Feb-13-17 Feb-21-17 Feb-27-17
55213 ABS 1826 1826 2795 2896 2,896 0 2,104 2,512 3,526
59381 ABS 8949 8949 8111 3984 6,294 6,619 7,472 6,668 5,807

I want to see the total weight of scrap, by material, that was added to inventory. Is there a way to use SUMIF/SUMIFS function to show total positive changes or something else? Is there a way to do it without adding a second column to capture the cumulative changes?

Any help would be greatly appreciated!