Phase 1 — Scratch
Welcome to the first phase of the From Scratch Programming Class. This is where you start.
What this phase is
Phase 1 teaches you the ideas of programming using a tool called Scratch. You don’t type code — you snap colorful blocks together. The blocks make a cat (and other characters) do things on a screen.
That probably sounds like a kid’s toy. It is, sort of. It’s also how millions of people learn to program for the first time, because Scratch lets you focus on the thinking part of programming without getting tangled up in typing, spelling, and weird symbols.
By the end of Phase 1, you’ll have built a complete, playable game of your own design. Then in Phase 2 we’ll switch to a real programming language (Python) — and you’ll discover that almost everything you learned in Scratch carries straight over.
What you’ll learn
The nine sessions of Phase 1 teach the core ideas every programmer uses, every day, for their entire career:
| Session | Idea | What it lets you do |
|---|---|---|
| 1 | Welcome & the peanut butter problem | Understand why precision matters in programming |
| 2 | Sequences | Tell sprites to do things, in order |
| 3 | Loops | Make sprites do something many times without writing it many times |
| 4 | Events | Control sprites in real time with the keyboard and mouse |
| 5 | Conditionals | Let your program decide what to do based on what’s happening |
| 6 | Variables | Make your program remember things, like a score |
| 7 | Putting it together | Combine everything into one small game |
| 8-9 | Milestone project | Plan, build, and demo a game of your own |
Every one of those concepts shows up again in Python (Phase 2-4), in desktop apps (Phase 5), in 2D games (Phase 6), in web pages (Phase 7), and in web applications (Phase 8). What changes is the language and the tools. The ideas are the same.
What you’ll build
By the end of Session 7, you’ll have built a small arcade-style game called Apples and Rocks: a cat that catches falling apples for points and dodges falling rocks (one rock and game over). Combines every idea from Sessions 2-6.
By the end of Session 9, you’ll have built a second game of your own design and shown it to the class. Could be a maze, a pet care game, a clicker, a story, a quiz — whatever you imagine, using everything you’ve learned.
What you’ll need
If you’re in the class at Old Zion Hill, the answer is: nothing. The class provides a computer with Scratch already installed, and you keep it.
If you’re following along on your own, you need:
- A computer (any computer — Windows, Mac, Linux, even a school Chromebook works).
- Either an internet connection (so you can use Scratch at scratch.mit.edu) or Scratch Desktop installed on your machine. The Installing on your own computer appendix has details.
How sessions work
Each session is one class meeting, about 90 to 120 minutes long. Every session has the same shape:
- Part A introduces a new idea with a guided exercise. If class gets cut short, Part A always stands on its own.
- Part B is open-ended practice or a project that uses Part A. Sometimes tiered into base / stretch / extension goals.
- Wrap-up is a few minutes of sharing what you did.
Each session also has an If you missed this session section near the end of the chapter — about 20 to 30 minutes of self-paced work that gets you ready for next week if you couldn’t make it.
Where to start
Session 1: Welcome & the peanut butter problem is where it begins. If you went to class, that’s the chapter that matches what we did. If you’re starting from this textbook on your own, that’s where to read first too.
When you’re stuck, the Getting unstuck appendix has a checklist that helps. The Glossary explains the vocabulary words we use in class.
Welcome. Let’s go.