Grading Program - Having a hard time

Question

Hi, I am making a grading program for my intro java class. We are required to make our own class and then use a "driver" class to test our template. The problem I am running into is that I do not know why some variables are being returned while others are not.
In the program, we are to create a class that gets the student id/quiz1 score, quiz2, midterm, and final. The grades are weighted. I will paste the StudentRecord class, the DriverStudentRecord, and then a sample output. Please help. I have been banging my head into this book but nothing is jumping out at me on how to fix it. Thanks!
StudentRecord
import java.util.*;
public class StudentRecord {
     private int studentID, quizOne, quizTwo, midTerm, finalExam, overallScore,
                 quizTotal;
     private char letterGrade;
     public void readInput()
          Scanner keyboard = new Scanner(System.in);
          System.out.println("Please enter the Student's ID#: ");
          studentID = keyboard.nextInt();
          System.out.println("Please enter the score for Quiz 1: ");
          quizOne = keyboard.nextInt();
          System.out.println("Please enter the score for Quiz 2: ");
          quizTwo = keyboard.nextInt();
          System.out.println("Please enter the score for the Midterm: ");
          midTerm = keyboard.nextInt();
          System.out.println("Please enter the score for the Final Exam: ");
          finalExam = keyboard.nextInt();
     public void calculation()
          quizTotal = quizOne + quizTwo;
          quizTotal = quizTotal * (25/100);
          midTerm = midTerm * (25/100);
          finalExam = finalExam * (50/100);
          overallScore = quizTotal + midTerm + finalExam;
     public char letterGrade()
          if (overallScore >= 90)
               return 'A';
          else if ((overallScore >= 80) && (overallScore < 90))
               return 'B';
          else if ((overallScore >= 70) && (overallScore < 80))
               return 'C';
          else if ((overallScore >= 60) && (overallScore < 70))
               return 'D';
          else if ((overallScore >= 0) && (overallScore < 60))
               return 'F';
          else
               return 'Z';
     public void writeOutput()
          System.out.println("Student# " + studentID + " grade report");
          System.out.println("Quiz one = " + quizOne);
          System.out.println("Quiz two = " + quizTwo);
          System.out.println("Quiz totals = " + quizTotal);
          System.out.println("Midterm = " + midTerm);
          System.out.println("Final = " + finalExam);
          System.out.println("Overall Score = " + overallScore);
          System.out.println("Final Letter Grade = " );
     }DriverStudentRecord
public class DriverStudentRecord {
     public static void main(String[] args) {
    StudentRecord testStudent = new StudentRecord();
    testStudent.readInput();
    testStudent.calculation();
    testStudent.letterGrade();
    testStudent.writeOutput();
}& Sample output
Please enter the Student's ID#:
999
Please enter the score for Quiz 1:
10
Please enter the score for Quiz 2:
8
Please enter the score for the Midterm:
90
Please enter the score for the Final Exam:
70
Student# 999 grade report
Quiz one = 10
Quiz two = 8
Quiz totals = 0
Midterm = 0
Final = 0
Overall Score = 0
Final Letter Grade =
Why are only quiz1 and 2 responses being carried over, but the rest are not? Does this look okay so far? I have never written my own class like this. Lastly, how do I get the letterGrade to print its return value? Thanks all! I really do appreciate it.

Answer 1

I went through uni with a chineese bloke, apparently
if you get less than 50% for anything (once) they
kick you out of school and make you a farmer. Tough
call on a six year old.
eristic,
I know you're learning, and you appear to be making
good progress, so feel free to ignore this small
criticism... your readInput and writeOutput methods
would be better placing in your driver class. Apart
from thay you're coming along fine.
1)
... do not alter thevalues of your quizes, midterm,and final.
Use the weights (25, 50, etc) in your finalcalculation only.
I think pete means (but I can't talk for him)
something like :    public void calculation()
score = (quiz1+quiz2)/4.0 + midTerm/4.0 +
finalExam/2.0;
}) You forgot something on this line:
System.out.println("Final Letter Grade = " );
test it... work out a bunch (6 should do) students
scores by hand, or with a calculator, or use excel...
and then run them through your program. Are the
answers what you expected?I was under the impression that the DriverStudentRecord is just a title for a test class? Instead of saying test, the prof. said Driver. Does driver mean something more than that? Also, I'm just following the structure that I've seen in my book so far. What advantage/benefit is there for putting those 2 in the driver? (that way I can understand why they are better suited there).