Excel

Open multiple files, view multiple worksheets, consolidate (add or subtract data automatically)

Viewing worksheets side by side,

Advanced filter using criteria.

Excel 2007 keyboard shortcuts.

To work out a discount or how much discount was taken. (FORMULAS IN BOTTOM TABLE)

Hiding zero values: http://www.techrepublic.com/blog/msoffice/three-ways-to-hide-zero-values-in-an-excel-sheet/8268

To hide inactive part of worksheet.

click on picture for clear instructions.