To quickly display all formulas in a worksheet, press Ctrl + ` (the button to the left of the number 1 on the keyboard). This enables you to check for consistency. If you have inherited the workbook, it quickly allows you to see how it was set up.
To see the data again, press Ctrl + ` again.
Alternatively, in Excel 2007, Excel 2010 and Excel 2013, on the Formulas tab, click Show Formulas in the Formula Auditing group.