Add calculator feature to Textbox like Quickbooks
All numeric textboxs in QB have a nifty feature. When you type a number and a function like "+", a mini dropdown calc will show. This is very handy for numeric data centric apps
Beth Massi commented
You can do this pretty easily with a custom command. See: http://blogs.msdn.com/b/bethmassi/archive/2011/10/06/i-command-you-lightswitch-screen-commands-tips-amp-tricks.aspx
Thanks for the suggestion!