# How do you add last digit of two numbers in python?

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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[0] and the last element of String using string[-1].

String Representation

## Python3

`number ``=` `1247`

`number ``=` `str``(number)`

`first_digit ``=` `int``(number[``0``])`

`last_digit ``=` `int``(number[``-``1``])`

`addition ``=` `first_digit ``+` `last_digit`

`print``(``'Addition of first and last digit of the number is'``,`

`      ``addition)`

Output:

Addition of first and last digit of the number is 8

Time complexity: O(1) since performing constant operations

Auxiliary Space: O(1) since using constant space for variables

### 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

`number ``=` `1247`

`res ``=` `number ``%` `10`

`while` `number > ``9``:`

`    ``number ``=` `number ``/``/` `10`

`res ``+``=` `number`

`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.

Auxiliary Space: O(1) since using constant space for variables

Python program to get an number n from user and display the last digit of n

Sample Input 1:

623

Sample Output 1:

3

Sample Input 2:

280

Sample Output 2:

0

#### Program or Solution

``` ```

``````

num=int(input("enter the number:"))
ldigit=num%10
print("last digit: {}".format(ldigit))

``````
``` ```

#### Program Explanation

Get a number num (using input() method) Seprate the last digit of number num by "digit = num%10".

(% by 10 always gives last digit of a number) print the digit (using print() method)

#### This Python program calculates sum of first and last digit of a given number.

In this program, we first read `number` from user. Then we reverse it using `[::-1]`. After reversing, we convert both `number` & `reverse` to integer using `int()` function. `first_digit` is obtained by `reverse%10` and `last_digit` is obtained by `number%10`. Finally we calculate sum of first & last digit to get final result.

## Python Source Code: Sum of First & Last Digit

``````
# Sum of first & last digit

number  = input("Enter number: ")

# Reversing number
reverse = number[::-1]

# Converting number and its reverse to integer
number = int(number)
reverse = int(reverse)

# Finding first digit
first_digit = reverse % 10

# Finding last digit
last_digit = number % 10

# Finding sum
total_sum = first_digit + last_digit

# Displaying sum
print("Sum of first & last digit of %d is %d" %(number, total_sum))
``````

## Output

```Enter number: 99975
Sum of first & last digit of 99975 is 14
```

### How do you take the last digit of a number in Python?

How to Get the Last Digit of a Decimal in Python.
pi = 3.141..
last_digit = int(repr(pi)[-1]).
print(f"The last digit of {pi} is {last_digit}").

### How do you sum a digit in Python?

The sum() method is used to compute the sum of digits of a number in python in a list. Convert the number to a string using str(), then strip the string and convert it to a list of numbers with the strip() and map() methods, respectively. Then, compute the total using the sum() method.

### How do I get the last 3 digits of a number in Python?

Use the modulo operator to get the last 3 digits of a number, e.g. last_three = number % 1000 . The modulo operator will return the last 3 digits of the number by calculating the remainder of dividing the number by 1000. Copied!

### How do you find the last two digits of a number?

Last two digits of a number is basically the tens place and units place digit of that number. So given a number say 1439, the last two digits of this number are 3 and 9, which is pretty straight forward.

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