Python Program to Calculate Sum of N Numbers

How to Calculate Sum of N Numbers

Calculating the sum of N numbers is a fundamental programming task. The process involves:

1. Collecting the numbers you want to sum
2. Initializing a sum variable to zero
3. Iterating through each number and adding it to the sum
4. Returning or displaying the final sum

This method works for any number of inputs, whether you know the count in advance or need to process an unknown quantity of numbers.

Python Program to Calculate Sum

Here's a complete Python program that calculates the sum of N numbers:

# Python program to calculate sum of N numbers
def calculate_sum():
    # Get the number of elements
    n = int(input("Enter the number of elements: "))

    # Initialize sum
    total = 0

    # Get numbers and add to total
    for i in range(n):
        num = float(input(f"Enter number {i+1}: "))
        total += num

    # Display the result
    print(f"The sum of {n} numbers is: {total}")

# Call the function
calculate_sum()

This program:

• Prompts the user for the count of numbers
• Uses a loop to collect each number
• Accumulates the sum in a variable
• Prints the final result

Worked Example

Let's walk through an example where we sum 3 numbers: 5, 10, and 15.

1. User enters 3 as the count of numbers
2. Program prompts for and receives 5, 10, and 15
3. Sum calculation: 0 + 5 = 5; 5 + 10 = 15; 15 + 15 = 30
4. Final output: "The sum of 3 numbers is: 30.0"

Formula Used

In the Python program, this is implemented through iteration and accumulation in a loop.