Sub input_output()
    Dim newrange_array()    'you will see this again later
    
    'First let's create a range that is input
    'One way to do this is to have the user select the range
    Dim rangein As Range
    Set rangein = Selection
    'That's all you have to do... now whatever the user had selected
    'before starting the program will be in the variable rangein
    
    'I now have a range in the variable rangein
    'I have no idea whether that range is a column
    'row, square, or rectangle...
    'but I can find out as follows
    
    Dim rows As Integer, cols As Integer
    'set up two variables to hold number of rows and columns
    
    'Now actually load up rows and cols with numerical values
    rows = rangein.rows.Count
    cols = rangein.Columns.Count
    
    
    'Now let's change the values in rows and columns somewhat
    'First we need a two-dimensional array to hold the values in
    ReDim newrange_array(rows, cols)
    'Notice it is redim... which means redimension... this forces a
    'dynamic array ... the only way this would work
    
    For i = 1 To rows
        For j = 1 To cols
            newrange_array(i, j) = rangein(i, j) / 2
        Next
    Next
    
    'now I would like to output the results somewhere
    Dim outsheet As String, outrange As String
    outsheet = "input_output" 'the name of the sheet where I want output
    outrange = "f18"
    'the name of the starting cell where I want output
    Set rangeout = Worksheets(outsheet).Range(outrange)
    'last line just creates the actual range
    
    For i = 1 To rows
        For j = 1 To cols
            rangeout(i, j) = newrange_array(i, j)
        Next
    Next
    
    'I'm done

End Sub