Session 11 — Tell an Animated Story

Duration: 60 min · Format: live online

Session goal: by the end, students have planned a 3-scene story and built it — a sprite that looks alive by switching costumes, characters that talk with say … for … seconds, and a broadcast [next scene] message that flips the backdrop and moves every sprite into the next scene together.

Soft skill focus — Creativity

Today's human skill: Creativity. A 3-scene story is a blank page — the characters, the scenes and what they say are entirely the student's to invent.

• Build it in class: during the paper-planning minutes, push students past their first idea — ask "what's a surprising place your character could end up?" before they lock in the three scenes.
• Reflection (wrap-up): ask "Where did an idea for your story come from, and how did you make it your own?"

Before class — prep

• Open Scratch in a tab (signed in so you can save) and be ready to screen-share the editor.
• Add a sprite with two or more costumes (the cat, or Cake, Ballerina, Dinosaur1 all have several) so you can demo the costume switch.
• Add two backdrops from the backdrop library (e.g. a room and a park) so you can demo changing scenes.
• Have the diagram below open to share (costumes make a sprite move, a broadcast changes the scene).

Hook

Ask the class (chat or unmute):

• "When you flip the pages of a flip-book really fast, the drawing seems to move. Why?"

Take two answers. Then reveal: "Each page is a tiny bit different, and flipping fast tricks your eyes into seeing movement. A Scratch sprite has costumes — its own little flip-book pages. Today we switch costumes to make a character walk and talk, then we'll change the whole scene to tell a real story from beginning to end."

Teach — Animate a sprite with costumes

Share this diagram and point to each idea as you name it:

Explain: every sprite has a Costumes tab (top-left, next to Code). A costume is one picture of the sprite. Switching between them quickly makes it look alive — walking, flapping, chomping.

Build this together on your shared screen. Pick a sprite with two costumes and build:

1. From Events (yellow), drag out when green flag clicked.

2. From Control (orange), snap forever under it.

3. From Looks (purple), drop next costume inside the forever loop.

4. Still inside the loop, add wait 0.3 seconds from Control so it's not a blur.

Your script reads:

when green flag clicked
forever
  next costume
  wait 0.3 seconds

Press the green flag. The sprite flips between its costumes on the spot — it looks like it's walking or dancing. Celebrate — that's animation!

Ask: "What would happen if we deleted the wait 0.3 seconds?" (Answer: the costumes flip too fast to see — a flickering blur. The wait sets the speed.)

Teach — Scenes: backdrops + broadcast

Explain: a story has scenes — the bedroom, then the park, then the beach. In Scratch the scene is the backdrop (bottom-right, next to the sprite list — the Stage has its own backdrops). To move to the next scene we don't just change the backdrop by hand — we send a message so everyone changes at once.

A broadcast is a shout everyone can hear. One sprite (or the stage) broadcasts a message like next scene; every sprite with a matching when I receive [next scene] hat block wakes up and does its part. That's how the backdrop, the cat, and the dog all switch scenes together — in sync.

Build this together. First, on the Stage, add a "scene changer":

1. Click the Stage (bottom-right). On its Code tab, from Events drag when I receive [next scene] (choose New message → type next scene).

2. Under it, from Looks, snap switch backdrop to [park].

Now make a sprite trigger it. Click your sprite and build:

3. From Events, drag when green flag clicked.

4. From Looks, add say [Let's go to the park!] for 2 seconds.

5. From Events, snap broadcast [next scene] under it.

The stage's script reads:

when I receive next scene
switch backdrop to park

And the sprite's script reads:

when green flag clicked
say "Let's go to the park!" for 2 seconds
broadcast next scene

Press the green flag. The sprite talks, then the broadcast fires and the backdrop flips to the park. Point out: the sprite sent the message, the stage heard it.

⚠ Watch for the mixed-up message name: broadcast and when I receive must use the exact same message. If you broadcast next scene but the stage is listening for Scene 2, nothing happens. Pick the message from the dropdown — don't retype it — so they always match.

Ask: "The dog sprite should also move when we reach the park. How does the dog know it's time?" (Answer: give the dog its own when I receive [next scene] hat block — everyone listening reacts.)

Activity — Plan & build a 3-scene story

Students plan first, then build. Planning on paper for 3 minutes makes the build go far smoother — insist on it.

Plan (3 min, on paper). Write three scenes in one line each:

• Scene 1: where are we, who's here, what do they say?
• Scene 2: the backdrop changes — what happens next?
• Scene 3: how does the story end?

Build (the rest):

1. Open a new project at Scratch. Add 3 backdrops (one per scene) and at least one sprite with 2+ costumes.
2. Animate your sprite: when green flag clicked → forever → next costume → wait 0.3 seconds.
3. Scene 1: give the sprite a say [ … ] for 2 seconds, then broadcast [scene 2].
4. On the Stage, add when I receive [scene 2] → switch backdrop to [your scene-2 backdrop]. Have a sprite say its scene-2 line, then broadcast [scene 3].
5. On the Stage, add when I receive [scene 3] → switch backdrop to [your scene-3 backdrop] and a final line.
6. Make it yours: add a second character that talks back, or a sound in one scene.

Circulate and ask: "Which sprite sends the message to change scenes? Who is listening for it?"

Debrief: ask 2–3 students to screen-share and play their story from the green flag. Applaud the scene changes.

Check for understanding

Ask these aloud or in the chat. Answer key (for you):

1. How do you make a sprite look like it's walking on the spot? → Switch its costumes in a loop — forever → next costume → wait a little.
2. You want the backdrop AND three sprites to change scene at the same moment. What block sends the signal? → broadcast — every sprite (and the stage) with a matching when I receive reacts together.
3. You broadcast scene 2 but nothing changes. What's the most likely reason? → The listener's message name doesn't match (or nothing has a when I receive [scene 2] hat). Make the names identical using the dropdown.

Wrap-up + homework

• Ask one student to explain, in one sentence, what a broadcast does.
• Homework — Finish your story: make sure all 3 scenes play from the green flag, each with at least one line of dialogue and one costume animation. Screenshot it for your portfolio.

Teaching notes

• Correct this misconception: "changing the backdrop moves the sprites too." It doesn't — the backdrop and each sprite are separate. A broadcast is what keeps them in sync: the stage switches the backdrop and each sprite runs its own when I receive script. If a sprite is stuck in the wrong scene, it's missing its own listener.
• Fast finishers (extension): add hide and show so a character only appears in the scenes it belongs to — when I receive [scene 2] → show, and hide it again in another scene. This is exactly how real cutscenes bring characters on and off "stage."
• Low-tech fallback: no devices? Fold paper into a 3-panel comic (three scenes). Students draw each scene and write one speech bubble per panel, then read it aloud left to right. The lesson — a story is scenes in order, each with characters that speak — is the real point; Scratch just animates it.

Vocabulary

Resources

• Scratch editor — where students build (free, in the browser).
• Scratch Ideas page — official tutorials, including "Make It Fly" and animation starter cards.
• Animate a Name (Scratch tutorial) — a gentle starter on costumes and looks.

Practice set

Extra tasks to explore costumes, backdrops and broadcasts. Work them easy → hard, at lab time or for homework. Answers follow each arrow.

1. Name that tab. Where do you find a sprite's different pictures? → The Costumes tab (top-left, next to Code).

2. Colour clue. Which colour block switches to the next costume? → Purple — Looks.

3. Fix it (spot the bug). A sprite's costumes flip so fast it's just a blur. What's missing? → A wait block inside the loop — add wait 0.3 seconds after next costume to slow it down.

4. Predict. A sprite runs say "Bye!" for 2 seconds → broadcast [scene 3], and the stage has when I receive [scene 3] → switch backdrop to [beach]. What happens? → The sprite says "Bye!", then the backdrop switches to the beach.

5. Make it (build task). Build a script so a sprite walks in place: keeps switching costumes forever with a short wait between. → when green flag clicked → forever → next costume → wait 0.3 seconds.

6. Two sprites, one signal (harder). A cat says its line, then the scene should change AND a dog should appear. Put the blocks with the right owner: broadcast [scene 2], when I receive [scene 2] → show, switch backdrop to [park]. → The cat ends with broadcast [scene 2]; the stage has when I receive [scene 2] → switch backdrop to [park]; the dog has when I receive [scene 2] → show. One broadcast, three listeners.

Going deeper (optional)

Optional — for a class that has a story playing and wants to make it feel like a real film.

Why broadcasts instead of just switching the backdrop? You could switch the backdrop by hand, but then every sprite would have to somehow know the scene changed. A broadcast is a single announcement that anything can listen to — the stage, the cat, the dog, a sound. Add one more listener and it joins the scene with zero changes to the sender. Real programs work this way too: one event, many reactions, all loosely connected. It's the same events idea from Unit 1, grown up.

Wait until a scene is done. If two things need to happen in order across sprites, use broadcast [next scene] and wait instead of plain broadcast. The sender pauses until every listener finishes, then carries on — perfect for "let this character finish talking before the next one starts."

Common mistakes & fixes

• Mistake: Broadcasting one message but listening for a different name, so nothing happens. → Fix: always pick the message from the dropdown in both blocks so the names match exactly.
• Mistake: A sprite appears in every scene because it never hides. → Fix: add hide/show inside the right when I receive scripts so it only appears where it belongs.
• Mistake: The costume loop never stops, so the sprite keeps flipping even during dialogue. → Fix: that's usually fine, but if it looks wrong, put the animation in its own script or use switch costume to for a still pose while talking.
• Mistake: Editing the backdrop scripts on a sprite instead of the Stage. → Fix: click the Stage thumbnail (bottom-right) first — backdrop switches live there.
• Mistake: All scenes fire at once because every broadcast is sent at the green flag. → Fix: chain them — Scene 1 broadcasts scene 2 after its dialogue; Scene 2's listener broadcasts scene 3, and so on.

Next session

Session 12 — Design & Showcase Your Game: students design their own game from a one-sentence idea, build and polish it, playtest it with a partner, fix the weakest part, and showcase it with pride.