Step 1: Understanding the Problem

To find the sum of digits, we need to extract each digit from the given number and sum them together. For example, the sum of digits in the number 123 would be 1 + 2 + 3 = 6.

Step 2: Developing the Algorithm

To solve the problem, we’ll use a loop to iterate through each digit of the number. We’ll extract the digits by performing modulo 10 operations and divide the number by 10 to move to the next digit. We’ll keep adding each digit to a running sum until all digits have been processed.

Step 3: Writing the Python Code

Let’s write the Python code to find the sum of digits:

def sum_of_digits(number):
    # Initialize the sum variable
    sum = 0

    # Iterate through each digit of the number
    while number > 0:
        # Extract the last digit using modulo 10
        digit = number % 10

        # Add the digit to the sum
        sum += digit

        # Remove the last digit from the number
        number = number // 10

    # Return the final sum
    return sum

# Test the function
number = 12345
result = sum_of_digits(number)
print("The sum of digits in", number, "is:", result)

O/P

The sum of digits in 12345 is: 15

Step 4: Code Explanation

Let’s go through the code step by step and explain how it finds the sum of digits in a given number:

1. The sum_of_digits function is defined, which takes a number as an argument.

2. Inside the function, we initialize a variable sum to 0. This variable will store the running sum of digits.

3. We enter a while loop that continues as long as the number is greater than 0.

4. Inside the loop, we extract the last digit of the number using the modulo (%) operator. For example, if the number is 123, number % 10 will give us the remainder 3.

5. We add the extracted digit to the sum variable.

6. We update the number by integer division (//) to remove the last digit. For example, if the number is 123, number // 10 will give us 12, effectively removing the last digit.

7. The loop continues until all digits have been processed, extracting each digit, adding it to the sum, and removing it from the number.

8. Once the loop completes, we return the final value of the sum.

9. Outside the function, we test the code by assigning a number (12345) to the number variable.

10. We call the sum_of_digits function with number as an argument and store the result in the result variable.

Finally, we print the result, which displays the sum of digits in the given number.

By using the modulo operator and integer division, the code effectively extracts the last digit from the number, adds it to the sum, and removes it from the number in each iteration. This process continues until all the digits have been processed, resulting in the sum of digits.

Step 5: Dry Run the Code

Certainly! Here’s a step-by-step explanation of the iteration process for n = 1235:

Iteration 1:

• Current number: 1235
• Extracted digit: 5
• Sum: 5
• Remaining number: 123

Iteration 2:

• Current number: 123
• Extracted digit: 3
• Sum: 5 + 3 = 8
• Remaining number: 12

Iteration 3:

• Current number: 12
• Extracted digit: 2
• Sum: 8 + 2 = 10
• Remaining number: 1

Iteration 4:

• Current number: 1
• Extracted digit: 1
• Sum: 10 + 1 = 11
• Remaining number: 0

The loop ends because there are no more digits left in the number.

The final sum of digits for n = 1235 is 11.

I hope this clarifies the iteration-wise explanation for calculating the sum of digits.

Feel free to modify and experiment with the code to gain a better understanding of how it works and explore other variations or optimizations.