Time to put it all together. You'll build a small calculator that:

1. Asks the user for two numbers
2. Asks which operation to perform
3. Prints the result

This uses every concept from Module 1: input(), type conversion, variables, f-strings, and arithmetic operators.

A quick preview: choosing between options

"Pick an operation" means our program needs to behave differently depending on what the user typed. That's normally Module 2 territory (if / elif / else), but here's a quick preview so you can finish the project now — we'll cover this properly, in depth, next module.

operation = "add"

if operation == "add":
    print("Adding!")
elif operation == "subtract":
    print("Subtracting!")
else:
    print("Unknown operation")

Read it like this: "if operation equals \"add\", do this; otherwise if it equals \"subtract\", do that; otherwise, do this last thing." == checks equality — it's different from the single = you use for assignment.

Building the calculator

num1 = float(input("First number: "))
num2 = float(input("Second number: "))
operation = input("Operation (+, -, *, /): ")

if operation == "+":
    result = num1 + num2
elif operation == "-":
    result = num1 - num2
elif operation == "*":
    result = num1 * num2
elif operation == "/":
    result = num1 / num2
else:
    result = "Unknown operation"

print(f"Result: {result}")

Walk through it: two input() calls collect numbers as text and immediately convert them with float(). A third input() collects the operator as a string. Then an if/elif chain picks the right arithmetic operator based on what the user typed, and an f-string prints the result.

Try it yourself

Run the calculator below. Try +, -, *, and / to make sure each branch works.

Module 1 complete

You now know how to store data in variables, work with Python's core types, convert between them, format strings, read input, and do arithmetic — and you've shipped a working program. That's the real foundation everything else builds on.

Next up: Module 2 — Control Flow, where if/elif/else and loops get the full treatment.