Formula to sum every nth row but not all the nth row

[Siyanna]

Hi

I have some numbers in column A (A1:A200)

I want to be able to add every 9 rows from A1 but not all the way

In cell C1 i have the number to determine how far i go down

so in this example say in C1 i have the number 1 the Return A2
if i have the number 2 then add A1 + A10
if i have the number 4 then add A1+A10+A19+A28 etc

hope this makes sense

 

[ravishankar]

Hi
try the following macro codes

Sub siyanna()
Dim total As Integer, a As Integer
total = 0
    For a = 1 To Cells(1, 3)
    total = total + Cells((a - 1) * 9 + 1, 1)
    Next a
MsgBox "The total of " & Cells(1, 3) & " rows is " & total
End Sub

ravishankar

 

[Siyanna]

Hi

can i do this with a formula please

 

[FormR]

can i do this with a formula please

Hi, here is one option you can try..

=SUMPRODUCT(--(MOD((ROW(A1:INDEX(A1:A200,((C1-1)*9)+1))-MIN(ROW(A1:INDEX(A1:A200,((C1-1)*9)+1)))+1)-1,9)=0),A1:INDEX(A1:A200,((C1-1)*9)+1))