This is a very ugly way and long way of doing the task... BUT, I tried to make it easy for you to understand.
Hope this helps.
Sub calcu()
Dim LastRow As Integer
Dim TotalofGtoJ as Interger
Dim TotalofKtoN as Interger
'Sheets(1) = DATA Sheet
'Sheets(2) = Result Sheet
'Could make this easier by declaring sheets with variables, but lets keep it simple :)
'Find Last Row of data in DATA sheet and store the ROW number as LastRow
LastRow = Sheets(1).Range("A9999").End(xlUp).Row
'x = 2, because we don't want to include your headers
For x = 2 To LastRow
'TotalofGtoJ is going to be the calculation of the four columns - same goes for TotalofKtoN
'There are LOADS of different ways to calculate columns, I will just use this way to make it easier to read
TotalofGtoJ = Sheets(1).Range("G" & x).Value + Sheets(1).Range("H" & x).Value + Sheets(1).Range("I" & x).Value + Sheets(1).Range("J" & x).Value
TotalofKtoN = Sheets(1).Range("K" & x).Value + Sheets(1).Range("L" & x).Value + Sheets(1).Range("M" & x).Value + Sheets(1).Range("N" & x).Value 'Add "+ Sheets(1).Range("O" & x).Value" if you want column O as well.
'I presume the number of columns will be exactly the same on the Data sheet as the Result sheet... So therefore, I will just use the value of x on both sheets.
Sheets(2).Range("I" & x).Value = TotalofGtoJ
Sheets(2).Range("H" & x).Value = TotalofKtoN
Next x
End Sub
You said, "Same process should be done for col K-N" ... But I saw that your spreadsheet 'Errors' columns actually go up to column O, but I done the code as requested. As it's quite simple to understand, you should be able to add column O if required by yourself :-)