Sub t()
Dim lr As Long, fn As Range
lr = Cells(Rows.Count, 1).End(xlUp).Row
Set fn = Range("A1:A" & lr).Find("0", , xlValues, xlWhole, xlByRows, xlPrevious)
If Not fn Is Nothing Then
Cells(2, 2) = Application.Sum(Range(fn, Cells(lr, 1)))
End If
End Sub