import java.util.Scanner;

public class TestScoreApp
{
   public static voice main(String[] args)
   {
     // display operational message
     System.out.println("Please enter test scores that range from 0 to 100.");
     System.out.println("To end the program enter 999.");
     System.out.println();  // print a blank line

     // initialize variables and create a Scanner object
     double scoreTotal = 0.0;
     int scoreCount    = 0;
     int testScore     = 0;
     Scanner sc = new Scanner(System.in);
 
     // get a series of test scores from the user
     while (testscore <= 100)
     {
       // get the input from the user
       System.out.print("Enter score: ");
       testScore = sc.nextInt();

       // accumulate score count and score total
       if (testScore <= 100)
       {
          scoreCount = scoreCount + 1;
          scoreTotal = scoreTotal + testScore;

       }       

     }
    // display the score count, score total, and average score
    double averageScore = scoreTotal / scoreCount;
    String message = "\n"
                   + "Score count: " + scoreCount + "\n"
                   + "Score total: " + scoreTotal +
"\n" 
                   + "Average score" + averageScore +
"\n";
    System.out.println(message);    

   }

}  

*******************************************************

output:

Please enter test scores that range from 0 to 100.
To end the program enter 999.

Enter score: 90
Enter score: 80
Enter score: 75
Enter score: 999

Score count: 3
Score total: 245.0
Average score: 81.66666666666667

Press any key to continue..._