For Exercises 15 through 28, use the incremental development methodology to implement th...

For Exercises 15 through 28, use the incremental development methodology to implement the program. Design a visually appealing GUI with Swing components and layout managers. For each exercise, identify the program tasks, create a design document with class descriptions, and draw the program diagram. Map out the development steps at the start. Present any design alternatives and justify your selection. Be sure to perform adequate testing at the end of each development step.

Write a TeachArithmeticFrame class that teaches children arithmetic. The frame uses a JLabel for a problem and a JTextField for the user answer. When the user presses the Enter key (while the JTextField object is active) or clicks the OK button, display a message stating whether the user’s answer is correct. When the Next button is clicked, display a new problem. The numbers are limited to two digits.

Consider using a larger font for the JLabel and JTextField text. You can change the color of text by calling the setForeground method, for example.

questionLbl.setForeground(Color.red);

Define a helper class that generates problems.