Add 1 to a cell value after dropdown list selection

First, this is not a good way to keep attendance as it is very easy to accidentally add extra days or make the wrong selection; in other words, this method is quite error-prone.

That said, here is a macro that should work for you:

Private Sub Worksheet_Change(ByVal Target As Range)

If Target.Column = 3 And Target.Row >= 7 Then

    If Target.Value = "Present" Then

        Cells(Target.Row, 4).Value = Cells(Target.Row, 4).Value + 1

    ElseIf Target.Value = "Absent" Then

        Cells(Target.Row, 5).Value = Cells(Target.Row, 5).Value + 1

    ElseIf Target.Value = "Sick" Then

        Cells(Target.Row, 6).Value = Cells(Target.Row, 6).Value + 1

    ElseIf Target.Value = "Away" Then

        Cells(Target.Row, 7).Value = Cells(Target.Row, 7).Value + 1

    End If

End If

End Sub

You were on the right path but you needed to put the macro into the worksheet where the code will run; after that, I just used a few IF statements to make the necessary checks.