Natural number

Natural numbers are numbers that are common and clear in nature. As such, it is a whole, non-negative number.

Logic

To print the sum of first N natural numbers, we need to run one loop from 1 to N, and each time inside the loop we have to add / sum value of “i” (current number) into one temporary variable.

Once the loop is over, outside of the loop we have to print a temporary variable containing the sum of natural numbers.

See also: Print first N natural numbers using for loop

Program

SumOfNatural.pyCopy
# Take number from user
num = int(input("Enter any number : "))

sum = 0;

for i in range(1, num + 1):
    sum += i

print("\nSum of first", num, "natural numbers :", sum)
Try It

Output

Enter any number : 50
Sum of first 50 natural numbers : 1275