text: 
  CREATE TABLE student_grades (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      name TEXT,
      number_grade INTEGER,
      fraction_completed REAL);
  
  INSERT INTO student_grades (name, number_grade, fraction_completed)
      VALUES ("Winston", 90, 0.805);
  INSERT INTO student_grades (name, number_grade, fraction_completed)
      VALUES ("Winnefer", 95, 0.901);
  INSERT INTO student_grades (name, number_grade, fraction_completed)
      VALUES ("Winsteen", 85, 0.906);
  INSERT INTO student_grades (name, number_grade, fraction_completed)
      VALUES ("Wincifer", 66, 0.7054);
  INSERT INTO student_grades (name, number_grade, fraction_completed)
      VALUES ("Winster", 76, 0.5013);
  INSERT INTO student_grades (name, number_grade, fraction_completed)
      VALUES ("Winstonia", 82, 0.9045);
  
  SELECT name,number_grade,ROUND(fraction_completed* 100) AS percent_completed
  FROM student_grades;
  
  SELECT COUNT(*),
   CASE
    WHEN number_grade > 90 THEN "A"
    WHEN number_grade > 80 THEN "B"
    WHEN number_grade > 70 THEN "C"
    ELSE "F"
    END AS "letter_grade"
    FROM student_grades
    GROUP BY letter_grade;
  