Edit Menu
  The Edit menu lets you undo Calculator operations, copy
  numbers from Calculator to other applications, and paste
  numbers or equations that have no variables from other
  applications into Calculator's accumulator.
  The Edit menu contains the following menu items:
      Undo
      Copy
      Paste
  For information about using the Edit menu items, double
  click on an item from the list of additional topics below.
  Additional topics:
  *   Undo
  *   Copy
  *   Paste
  *   File Menu
  *   Help Menu
  *   Mode Menu
  *   Undoing the Most Recently Performed Function
  *   Copying Numbers from Other Applications
  *   Copying Numbers to Other Applications
  *   Overview of Calculator