The "Pivot-Calculator-Concept" picture is what I have in mind to implement as a small tutorial.

Add the new directory:
svn mkdir -m "Adding a new calculator directory to Pivot tutorials." https://svn.apache.org/repos/asf/pivot/trunk/tutorials/src/org/apache/pivot/tutorials/calculator

Committed revision 1687873.

In trunk:
Sending LICENSE
Adding tutorials/src/org/apache/pivot/tutorials/calculator/Calculator.java
Adding (bin) tutorials/src/org/apache/pivot/tutorials/calculator/asterisk_orange.png
Adding tutorials/src/org/apache/pivot/tutorials/calculator/calculator.bxml
Adding tutorials/src/org/apache/pivot/tutorials/calculator/calculator_styles.json
Sending wtk/src/org/apache/pivot/wtk/Keyboard.java
Transmitting file data ......
Committed revision 1687874.

See the commit message for 1687874 for details on what (I see) is still left to do here.

Fixed a bug with the percent calculations.
Sending org/apache/pivot/tutorials/calculator/Calculator.java
Transmitting file data .
Committed revision 1688306.

Fix a few more bugs:
Sending org/apache/pivot/tutorials/calculator/Calculator.java
Sending org/apache/pivot/tutorials/calculator/calculator_styles.json
Transmitting file data ..
Committed revision 1688484.

Merged to branches/2.0.x with the following revisions:
1703262
1703265
1703266
1703267

Had to make a small modification in branches/2.0.x to work around a javac compiler issue with Java 6.
Revision 1703273.

There may be some small issues with the actual calculator logic, but I'm going to close this issue because the app (as a tutorial) is very functional right now.