
Option Explicit
Sub abc()
Dim a, i, j
a = Range("a2:c" & [a1].End(xlDown).Row).Value
ReDim b(1 To UBound(a) - 1, 1 To 1), c(1 To 3)
For i = 2 To UBound(a)
For j = 1 To 3
c(j) = (a(1, j) + a(i, j)) Mod 10
Next
b(i - 1, 1) = Join(c, vbNullString)
Next
[d3].Resize(UBound(b)) = b
End Sub