HW03 判斷敘述式

HW03 判斷敘述式 115103136余廷宥

1.NotebookLM

2.影片

3.學習卡與測驗

4.寫1個程式需附加說明 Create a README For Github

2. Calculate the Sum of Digits of a Four-Digit Number

📌 Description

This Python program reads a four-digit number from the keyboard and calculates the sum of its individual digits.

For example, if the user enters 4225, the sum of its digits is:

4 + 2 + 2 + 5 = 13

💻 Python Code

num = int(input('Enter 4 digit number: '))

print('Entered number is:', num)

r1 = num % 10
q1 = num // 10

r2 = q1 % 10
q2 = q1 // 10

r3 = q2 % 10
q3 = q2 // 10

r4 = q3 % 10

print('Sum of all the digits within number', num,
      'is:', r1 + r2 + r3 + r4)

🧮 Logic and Formula

The program uses two mathematical operators:

• % (Modulus): Gets the remainder, which is used to extract the last digit.
• // (Floor Division): Removes the last digit by dividing by 10 and keeping the integer part.

For the number 4225:

Step	Calculation	Result
1	4225 % 10	5
2	4225 // 10	422
3	422 % 10	2
4	422 // 10	42
5	42 % 10	2
6	42 // 10	4
7	4 % 10	4

Sum of digits = 5 + 2 + 2 + 4 = 13

▶️ Example Output

Enter 4 digit number: 4225
Entered number is: 4225
Sum of all the digits within number 4225 is: 13

📝 Explanation

1. input() asks the user to enter a four-digit number.
2. int() converts the input into an integer.
3. % 10 extracts the last digit of a number.
4. // 10 removes the last digit.
5. The program repeats these operations to extract all four digits.
6. The + operator adds the four digits together.
7. print() displays the original number and the sum of its digits.

🛠️ Requirements

• Python 3.x

🚀 How to Run

1. Save the program as sum_of_digits.py.
2. Open a terminal or command prompt.
3. Run the following command:

python sum_of_digits.py

📚 Learning Objectives

• Reading keyboard input in Python.
• Using the modulus operator (%).
• Using floor division (//).
• Extracting individual digits from a number.
• Performing arithmetic calculations.

📄 License

This project is for educational purposes.