A spreadsheet on a computer screen displays a table with columns labeled 'Item', 'Quantity', 'Unit Price', 'Total', and 'Total Cost'. The table contains rows of data with various items and their corresponding quantities, unit prices, and totals. The spreadsheet also includes a header with the title 'Invoice Month: September 2013' and a footer with the text 'Normal Working Hours: Monday to Friday 9am to 5pm'. The spreadsheet is open in a Microsoft Excel program.