🎯 Checkpoint: the basics
Why: Prove the basics stuck: print, input, variables, numbers.
Unlocks: Decisions and loops — with a solid floor under your feet.
Nothing new in this lesson — on purpose. You've written four lessons of real Python: printing, listening, remembering, calculating. Before we teach the machine to decide, let's make sure all four are truly yours. A quick cheat sheet, a few questions, one repair job. If anything feels shaky, that's not failure — that's the checkpoint doing its job: go replay that lesson, it takes five minutes.
| Tool | What it does | Example |
|---|---|---|
| print(...) | Says something on screen | print("Hello, world!") |
| input() | Pauses and waits for the human to type | name = input() |
| = (variable) | Saves a value into a labeled box | age = 30 |
| int(...) | Turns text into a whole number | age = int(input()) |
| + - * / ** | Real arithmetic | 7 / 2 is 3.5, 2 ** 10 is 1024 |
| "..." + "..." | Glues text together | first + " " + last |
What does this program print?
The user types 5 when this runs. Why does it crash?
Which line prints exactly 3.5?
Final task — from memory. Remember the broken bill? This program has the same disease: 4 friends share a 120 bill, but the math is wrong. Fix it so it prints each friend's fair share: 30.0.
Checkpoint cleared 🎉 You can speak, listen, remember and calculate — the four muscles every program ever written is built from. Next section: teaching the machine to choose.