The main window is divided into three regions:-

       +------------------------------------------------------------------+
       | +--------------------------------------------------------------+ |
       | |                         STATUS BAR                           | |
       | +--------------------------------------------------------------+ |
       |                                                                  |
       | +--------------------------------------------------------------+ |
       | |                                                              | |
       | |                         CURRENT EQUATION                      | |
       | |                                                              | |
       | +--------------------------------------------------------------+ |
       |                                                                  |
       | +--------------------------------------------------------------+ |
       | |                                                              | |
       | |  < ^ O v > Otherside 1/x <=> x-� Multiply  Factorize  | |
       | |  Both Sides Substitute Evaluate   Simplify  Group     | |
       | |  Diff'ate  Integrate Trig     Algebra   New Expr   | |
       | |                                                              | |
       | |  Store       Review       Undo          Help            | |
       | |                                                              | |
       | +--------------------------------------------------------------+ |
       |                                                                  |
       +------------------------------------------------------------------+

There is also a  menu strip to access the more esoteric features.