This method retrieves the grade level of a student. For example, it might return "10" for a sophomore or "12" for a senior.
getName method: This method retrieves the name of a student. It returns the full name as stored in the system, such as "John Doe" or "Jane Smith".
calculateAverage method: This method calculates the average score of multiple assignments for a student. It takes into account all the grades received and provides an overall average score.