### Java Program to Find Sum of Natural Numbers

Natural numbers are a set of positive integers starting from 1, and they go like 1, 2, 3, 4, 5, ... and so on. Sometimes in programming, we come across a need to compute the sum of the first 'n' natural numbers. In this blog post, we will understand and create a Java program that does just that!

# The Mathematical Approach

Mathematically, the sum of the first 'n' natural numbers can be found using a simple formula:

Sum=2n(n+1)

For example, if we want to find the sum of the first 5 natural numbers:

Sum=25(5+1)=15

# Java Program to Find Sum of Natural Numbers

import java.util.Scanner;

public class NaturalNumberSum {

public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Enter the number up to which you want the sum:");
int n = scanner.nextInt();

int sum = calculateSum(n);
System.out.println("The sum of the first " + n + " natural numbers is: " + sum);
}

public static int calculateSum(int n) {
return n * (n + 1) / 2;
}
}

## Output:

Enter the number up to which you want the sum:
100
The sum of the first 100 natural numbers is: 5050

## Step by Step Explanation:

User Input:

        Scanner scanner = new Scanner(System.in);
System.out.println("Enter the number up to which you want the sum:");
int n = scanner.nextInt();

We are using Java's Scanner class to take user input. Here, we prompt the user to enter a number n up to which they want to calculate the sum.

Function to Calculate Sum:

    public static int calculateSum(int n) {
return n * (n + 1) / 2;
}

This function takes in a number n and calculates the sum of the first n natural numbers using the formula mentioned above.

Displaying the Result:

        int sum = calculateSum(n);
System.out.println("The sum of the first " + n + " natural numbers is: " + sum);

We call our calculateSum function to get the sum and then display it to the user.

# Conclusion

Computing the sum of natural numbers is one of the basic mathematical operations that showcases the power of mathematical formulas in programming. This article offers a simple approach to implement this operation in Java. It serves as a foundational step for newcomers to understand how mathematical concepts and programming go hand in hand. Happy coding!