Using the Calculator in the Vantage Lite.
The calculator works just like many other calculators on the market. The screen you see here shows the regular calculator. There is also a scientific calculator for more advanced/technical problem-solving.
CLEAR clears the current entry.
ALL CLEAR clears an entire problem.
Always activate the ALL CLEAR key before starting any new problem.
The OK Key:
The OK key exits you from the calculator and returns you to the workspace or to an open Notebook. It also copies the answer to your last problem and puts it in the Text Display Area of your workspace or Notebook.
If you want to exit the Calculator without copying an answer:
Activate the Cancel key at any time.
You can also activate the ALL CLEAR key to clear a problem and then activate the OK or Cancel keys.
Note: If you do not want your device to speak the problems, turn the speech to Off.
An Addition Problem:
Open the CALCULATOR in the TOOLBOX.
Activate the ALL CLEAR key.
Activate 2+2=4. Did you notice that each time you activate a new key, the screen clears and the latest number is added to the screen? When you activate the = key, the answer to the problem is visible in the display.
A Square Root Problem: 
Activate the ALL CLEAR key.
Activate 4.
Activate the SQUARE ROOT key.
The number 2 appears in the display area.
If you make a mistake: activate the CLEAR or DELETE CHAR key to clear the last entry. Activate the ALL CLEAR key to clear the entire problem and to start over.
Scientific Calculator gives you more options to work with. See more examples below:
Note: Is you are using a switch to scan the calculator, turn Predictive Selection ON in Access Method menu to skip over all the empty locations to the left and right of the calculator.