Forum Discussion
J4_ck
Feb 16, 2019Copper Contributor
Adding Nth Cells
Hello, Im pretty new to excel, can anyone give me a hand? Im trying to add up every 3rd cell in my table. (Looking at cell E3, addind up "product focus sales" for each week. for each person) ...
SergeiBaklan
Feb 16, 2019Diamond Contributor
Hi,
With SUM you shall use array formula (Ctrl+Shift+Enter), but SUMPRODUCT returns correct result. 0.0347 that's just 3.47% which is correctly sums 0.3% in E14, and 3.17% in E17, all the rest are zero.
Please check attached.
- TwifooFeb 19, 2019Silver ContributorThe 2nd formula is correct. Your aim is to add every 3rd row starting with the 8th row. Thus, you must adjust the row numbers to become divisible by 3.
By subtracting 5, row numbers 6:110 were converted to 1:105. You can also achieve the same result by subtracting 2 or by adding 1 to the row numbers, as follows:
1. Subtract 2: =SUMPRODUCT(E6:E110,
--(MOD(ROW(E6:E110)-2,3)=0)); or
2. Add 1: =SUMPRODUCT(E6:E110,
--(MOD(ROW(E6:E110)+1,3)=0))