public class Grade
{
	private int Math;     //instance variable
	private int English;  //instance variable
	private String name;  //instance variable
	
	//Constructor
	public Grade(String aName, int aMath, int aEnglish)
	{
		name = aName;
		Math = aMath;
		English = aEnglish;
	}
	//Constructor overload
	public Grade(String aName)
	{
		name = aName;
		Math = 0;
		English = 0;
	}
	// return the average score of Math and English
	public double getAverage()
	{
		return (Math + English) / 2.0;
	}
	// get bonus score for Math
	public void MathBonus(int M)
	{
		Math += M;
	}
	//get bonus score for English
	public void EnglishBonus(int E)
	{
		English += E;
	}
	//print the information
	public void printData()
	{
		System.out.printf("Name:  %s\n", name);
		System.out.printf("Math:  %d\n", Math);
		System.out.printf("English: %d\n", English);
	}	
}

// How to declare an object.

// How to call a math.

public class Test
{
   public static void main(String[] args)
   {
	Grade obj1 = new Grade("Jennifer", 75, 88);
	obj1.printData();
	System.out.printf("The average is %.1f\n", obj1.getAverage());
	obj1.MathBonus(10);
	obj1.printData();
	System.out.printf("The average is %.1f\n", obj1.getAverage());
		
	Grade obj2 = new Grade("Robert");
	obj2.printData();
	System.out.printf("The average is %.1f\n", obj2.getAverage());

    }

}

You save both files in a folder.
Under that folder, you compile both file by the statement below:
javac *.java
Then, you run the file having main method as below.
java Test