How to **find the sum and average of first n natural numbers in Python**? In this article, we are going to write a Python code to calculate the sum and average of the positive numbers starting from 1 to the given number (n) using for loop.

- The article is part of
**Python Basics**. - Solve our
**Python Basic Exercise for Beginners**and**Python Quiz for Beginners**to practice Python essential skills.

## Algorithm to calculate the sum and average of first n natural numbers

- Allows a user to enter the number (n) he wishes to calculate the sum and average. The program accepts user input using the input function.
- Next, run loop till the entered number using the for loop and range() function.
- Next, calculate the sum using a
`sum = sum + current number`

formula. - At last, after the loop ends, calculate the average using
`average = sum / n`

.`n`

is a number entered by the user.

## Python Program to calculate the Sum

n = input("Enter Number to calculate sum") n = int (n) average = 0 sum = 0 for num in range(0, n+1, 1): sum = sum+num print("SUM of first ", n, "numbers is: ", sum )

**Output**: Run Online

Enter Number to calculate sum 5 Sum of first 5 number is: 15

Note: The above program loops from 1 to the number entered by the user and adds all numbers to the variable sum.

## Python Program to calculate average

print ("calculate an average of first n natural numbers") n = input("Enter Number ") n = int (n) average = 0 sum = 0 for num in range(0,n+1,1): sum = sum+num; average = sum / n print("Average of first ", n, "number is: ", average)

**Output**: Run Online

calculate an average of first n natural numbers Enter Number 10 Average of first 10 number is: 5.5

Note: The above program loops from 1 to the number entered by the user and add the current number to the variable sum. After the loop ends, we calculated the average.

If you want to calculate the sum and average of multiple user-entered numbers then please refer to this.

## Calculate the sum and average of a given list in Python

Let see you have a list of numbers and you want to calculate the sum of numbers present in the list.

- All you need to do is to iterate a list using a for loop and add each number to a sum variable.
- To calculate the average divide the sum by the length of a given list(total numbers in a list)

Let see this with an example.

Program 1:

sum = 0 list = [11,22,33,44,55,66,77] for num in list: sum = sum +num average = sum / len(list) print ("sum of list element is : ", sum) print ("Average of list element is ", average )

**Output**: Run Online

sum of list element is : 308 Average of list element is 44.0

If you want to calculate the sum and average of multiple user-entered numbers then please refer to this.

## Calculate sum using the built-in sum function in Python

Let’s see how to use a `sum()`

function to calculate the sum.

print ("Sum of range of numbers: ", sum(range(1, 5)))

**Output**: Run Online

Sum of range of numbers: 10

## Python while loop to calculate sum and average

You can also use the while loop to calculate the sum and average of n numbers. Here, n can be 2, 5 or any number. Follow these steps:

- Take a value of n =20
- Run while loop until n is greater than zero
- Add the current value of n to sum variable. Also, decrement n by 1 in while loop body
- calculates the average by dividing the sum by total numbers.

Let see the demo to calculate the sum and average using the while loop.

n = 20 total_numbers = n sum=0 while (n >= 0): sum += n n-=1 print ("sum using while loop ", sum) average = sum / total_numbers print("Average using a while loop ", average)

**Output**: Run Online

sum using while loop 210 Average using a while loop 10.5

### Practice Problem: Add Two Matrices in Python

matrixOne = [[6,9,11], [2 ,3,8]] matrixTwo = [[15,18,11], [26,16,19]] result = [[0,0,0], [0,0,0]] # First iterate rows for i in range(len(matrixOne)): # Second iterate columns for j in range(len(matrixOne[0])): result[i][j] = matrixOne[i][j] + matrixTwo[i][j] print("Addition of two Matrix In Python") for res in result: print(res)

## Next Steps

To practice what you learned in this article, I have created a Python Basic **Quiz and Exercise**.

- Solve our
**Python essential exercise for beginners**to have a better understanding of Python’s basic concepts. - Solve our
**Basic Python Quiz for beginners**to test your fundamental Python skills.

Let me know your comments and feedback in the section below.