Thread: writing a method to add fractions?

Okay so I have to write a method to compute the following series: m(i)= 1/3 + 2/5 +....+ (i / 2i+1) and write a test program that displays a table " i = m(i)" 1=0.3333 2=0.7333....all the way down to 20 which is 9.2480. I have written something and cannot seem to get the sum of the fractions to display . I could be going about this the completely wrong way but this was my attempt. Please give suggestions!

public class ExtraCredit1
{
	public static void main(String[] args)
	{
		double num;
		double sum = 1;
 
	for (int i = 1; i <= 20; i++)
	{
		System.out.println("" + i + " " + sum + "");
	}
}
	public static double m(double i)
	{
		double sum = 1;
	    sum += (double) i / (2*i + 1);
 
		return sum;
	}
}

When I compile it shows the 'i' = 1,2,3,4....20 but the m(i) is 0,0,0,0.... and needs to be 0.3333, 0.7333.... all the way to 9.2480... its supposed to add all the fractions together and display... 1/3 = 0.3333, 1/3 + 2/5 = 0.7333...

Its not supposed to show the actual fraction in the output just;
i m(i)
1 = 0.3333
2 = 0.7333
3
4

output1.jpg

I understand it is a poor name for a method however thats what the teachers instruction are. Do I need to call the method into my println?

--- Update ---

import java.text.DecimalFormat;
 
public class ExtraCredit1
{
	public static void main(String[] args)
	{
		double num;
		double sum = 0;
 
	DecimalFormat formatter = new DecimalFormat("0.0000");
 
	for (int i = 1; i <= 20; i++)
	{
		System.out.println("" + i + "  =  " + formatter.format(m(i)) + "");
	}
}
	public static double m(double i)
	{
		double sum = 0;
	    sum += (double) i / (2*i + 1);
 
		return sum;
	}
}

--- Update ---

now it displays the fractions but it isnt adding them up after each iteration

okay so....

	public static double m(double i)
	{
		double sum = 0;
	    sum += (double) (i / (2*i + 1));
            total = sum + sum
		return total; //Will this return the accumulative total?
	}
}

--- Update ---

no that doesnt work either... hmm