Sum of First n Natural Numbers
To find the sum of the first n natural numbers, we can use a simple formula that involves the arithmetic progression. The sum of the first n natural numbers is given by the formula:

Sum = n * (n + 1) / 2
Let's break down the explanation further:

Understanding the Formula:
- The formula n * (n + 1) / 2 can be derived from the concept of arithmetic progression, where the sum of an arithmetic series is given by the formula: n/2 * (first term + last term).
- In this case, the first term is 1 and the last term is n. So, the sum of the first n natural numbers becomes n/2 * (1 + n) which simplifies to n * (n + 1) / 2.

Example:
- For example, if we want to find the sum of the first 5 natural numbers, we substitute n = 5 into the formula: 5 * (5 + 1) / 2 = 5 * 6 / 2 = 15.

Importance:
- This formula is important in various mathematical calculations and is commonly used in mathematical problems, series, and sequences.

Conclusion:
- Understanding the formula for finding the sum of the first n natural numbers is essential in mathematics and can simplify calculations involving series and sequences. Practice applying this formula to various values of n to reinforce your understanding.