public class TGIF {
  public static void main(String[] args) {
    double width = 3.5;
    double height = 2.0;
    // caluculate area
    double area;
    area = width * height;
    System.out.println("area is " + area);
    // caluculate perimeter\
    double perimeter = (2 * width) + (2 * height);
    System.out.println("perimeter is " + perimeter);
    
    // find digits of a 4-digit number
    int number = 5678;
    int saved = number;
    System.out.println("number is " + number);
    int digit = number % 10;
    System.out.println("ones digit is " + digit);
    number = number / 10;  // or number /= 10;
    System.out.println("number is now " + number);
    digit = number % 10;
    System.out.println("tens digit is " + digit);
    number = number / 10;
    System.out.println("number is now " + number);
    digit = number % 10;
    System.out.println("hundreds digit is " + digit);
    System.out.println("saved is still " + saved);
  }
}