MoboMath operates on "digital ink", generated by writing with a special pen on your screen (if you have a tablet PC) or on an external graphics tablet.
On most tablets, when you move the pen above the surface, you will see the mouse pointer move around the screen. Moving the pen just above the tablet is the same as moving the mouse, and pressing the pen tip down on the tablet is the same as pressing the mouse button.
Some touch-screen tablets do not detect pen movements above the tablet surface, but they still register pen taps as clicks and pen strokes as ink input.
Unlike a mouse, the pen is based on absolute positioning – the location of the pointer is determined by the position of the pen on the tablet, not just by relative motion. This feels very natural when writing on the screen but may require practice if your are using an external tablet for the first time.
Using the pen in MoboMath
If you are unaccustomed to using a tablet, you can practice with MoboMath now. First move the pen above the tablet to see if the mouse pointer moves. Then try writing in the MoboMath window by pressing down while you move the pen. You should see digital ink appear as you write.
Next, clear the ink in the MoboMath window by tapping the 
Clear Page button with your pen tip.
Now try writing a simple expression such as a+b in the MoboMath window. If you are writing and make a mistake, you can back up by tapping the 
Undo button. Try it now – tap the Undo button repeatedly, until you once more have an empty window. Each time you tap Undo the most recent stroke still showing disappears. If you tap Undo one more time, you will see the ink you erased with the Clear Page command. You can use Undo to reverse any action, not just new pen strokes.
Now tap the 
Redo button repeatedly to restore the display to its prior state. When there is nothing left to restore, the Redo button will be disabled.
You can also use the pen to access the MoboMath menu items available in the menu bar. To access context menus in MoboMath, you can either press and hold down the pen on a tablet PC or, if your pen has a button on its side, press that button while tapping.
For best results, see these important guidelines for successful pen input using MoboMath.