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1. Print "Hello, World!"2. Add Two Numbers3. Swap Two Variables4. Find ASCII Value of a Character5. Check Even or Odd6. Find Largest of Two Numbers7. Find Largest of Three Numbers8. Check Positive, Negative, or Zero9. Convert Kilometers to Miles10. Convert Celsius to Fahrenheit11. Calculate Area of a Triangle12. Calculate Simple Interest13. Calculate Compound Interest14. Calculate Square Root15. Convert Seconds to Hours, Minutes, and Seconds16. Calculate Body Mass Index (BMI)17. Check Leap Year18. Find Absolute Value19. Calculate Age from Birth Year20. Sum of First N Natural Numbers21. Calculate Power Without Using pow()22. Print Multiplication Table23. Convert Decimal to Binary24. Convert Binary to Decimal25. Calculate Electricity Bill

Add Two Numbers in Python

input() gives strings. Forget float() and you glue 10 and 20 into 1020.

BeginnerBasic Python ProgramsExample 2 of 25
add-two-numbers.py
1# Program to add two numbers provided by the user
2

3# taking input from the user
4num1 = float(input("Enter first number: "))
5num2 = float(input("Enter second number: "))
6

7# adding the two numbers
8result = num1 + num2
9

10# displaying the result
11print("The sum is:", result)

Output

Enter first number: 10
Enter second number: 20
The sum is: 30.0

In this one

  • input() is a string until you convert it
  • float("10") + float("20") is 30.0, not "1020"

What's going on

input() always returns a string. "10" + "20" is "1020", not 30. That one surprises everyone once.

float(...) turns the string into a number so + actually adds. Use int() if you only want whole numbers — then 10.5 will crash.

The shape is boring on purpose: read, convert, compute, print. You will copy this 50 times.

After this program

If the idea is still fuzzy, read Day 1: Introduction to Python in the Python course. For a short check, try the Python quiz (300 questions). Stay with all 25 basic python programs, or see every topic on Python exercises.

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