Related Articles

# Python Program to Find Sum of First and Last Digit

• Last Updated : 23 Aug, 2021

Given a positive integer N(at least contain two digits). The task is to write a Python program to add the first and last digit of the given number N.

Examples:

Input: N = 1247

Output: 8

Explanation: First digit is 1 and Last digit is 7. So, addition of these two (1 + 7) is equal to 8.

Input: N = 73

Output: 10

## Method 1: String implementation

• Take input in the form of String or typecast given input in String.
• Now pick the 0th index of the String and typecast it into Integer and store it in a variable.
• The same thing with the -1st index and also store in another variable.
• Now add these two variables and
• print them as an Output.

Note:  We can access the first element of String using string and the last element of String using string[-1]. String Representation

## Python3

 `# We have a number``number ``=` `1247`` ` `# We are type casting it in string``number ``=` `str``(number)`` ` `# Storing first and last digit in a variable``# after type casting into Integer.``first_digit ``=` `int``(number[``0``])``last_digit ``=` `int``(number[``-``1``])`` ` `# Adding these two variables``addition ``=` `first_digit ``+` `last_digit`` ` `# Display our output``print``(``'Addition of first and last digit of the number is'``, ``      ``addition)`

Output:

Addition of first and last digit of the number is 8

## Method 2: Solve it using an integer

• We have given a positive Integer.
• After dividing by 10, store the remainder in a result variable.
• Continue the loop until the number becomes less than 9.
• Each time in the loop, divide the number by 10(integer division).
• After the end of the loop.
• Add the number in the result variable.
• Display the result variable as the output.

Note: Whenever we divide any number with 10, we get the last digit as the remainder. If we divide any number with 100, we get the last two-digit as the remainder.

## Python3

 `# We have a number.``number ``=` `1247`` ` `# Assigning last digit of the number in res``# variable.``res ``=` `number ``%` `10`` ` `# Now, continue a loop until``# the number becomes less than 9.``while` `number > ``9``:`` ` `    ``# integer division of the number and reassigning``    ``# it.``    ``number ``=` `number ``/``/` `10`` ` `# Here, our number only contain one digit.``# So, add this number in res variable.``res ``+``=` `number`` ` `# Now, display our output``print``(``'Addition of first and last digit of number is'``, res)`

Output:

`Addition of first and last digit of the number is 8`

Time Complexity: O(n), where n is how many digits are there in the given number.

Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning – Basic Level Course

My Personal Notes arrow_drop_up