Motion Blocks and Block Categories¶

Summary¶

Explores motion blocks in depth, block categories, shapes, colors, and the blocks palette organization. This chapter covers 10 concepts from the learning graph, building on prerequisite concepts from earlier chapters.

Concepts Covered¶

This chapter covers the following 10 concepts from the learning graph:

Hat Block Shape
Stack Block Shape
Reporter Block Shape
Boolean Block Shape
Cap Block Shape
Add Extension
Script Area
Costume Center
Sound Blocks
Backpack

Prerequisites¶

This chapter builds on concepts from:

1. Welcome to Scratch

Block Shapes — The Secret Language of Scratch¶

In Chapters 1 and 2, you saw that blocks come in different shapes. These shapes aren't just for looks — they tell you exactly how the block works and where it can go in a script.

Think of block shapes like puzzle pieces — each shape has a specific job and only fits in certain places.

The Five Block Shapes¶

1. Hat Blocks 🎩 — The Script Starters¶

Shape: Rounded top, flat bottom (like a hat!)

Job: Start a script when something happens. Every script MUST begin with a hat block.

Where they go: ONLY at the very top of a script. Nothing can go above them!

Examples: - when green flag clicked 🟢 - when this sprite clicked 👆 - when [space] key pressed ⌨️ - when I receive [message] 📡

🎩 One Hat Per Script

Every separate script stack needs its own hat block. You can't have two hat blocks in the same stack!

2. Stack Blocks 🧱 — The Action Doers¶

Shape: Puzzle-piece notches on top AND bottom (like a brick!)

Job: Do something — move, turn, say, wait, change a variable, play a sound, etc.

Where they go: In the middle of a script, snapped between other stack blocks or under a hat block.

Examples: - move 10 steps 🔵 - say Hello! 🟣 - play sound pop 🩷 - wait 1 seconds 🟠 - change x by 10 🔵 - set score to 0 🔴

🧱 Stack Blocks Chain Together

Stack blocks snap together vertically — the bottom notch of one fits into the top notch of the next. They run in order, top to bottom.

3. Reporter Blocks 📊 — The Value Givers¶

Shape: Rounded rectangle (like a pill!)

Job: Give a value — a number or text — that other blocks can use.

Where they go: Inside the white holes (slots) of other blocks. They don't stand alone!

Examples: - x position 🔵 — gives current X coordinate - y position 🔵 — gives current Y coordinate - direction 🔵 — gives current facing angle - pick random 1 to 10 🟢 — gives random number - timer 🟡 — gives seconds since green flag - answer 🔷 — gives what player typed

📊 Reporters Fit Inside Slots

See those white oval/rectangular holes in other blocks? That's where reporter blocks go!

go to x: (x position) y: (y position)
                ↑           ↑
          reporter      reporter

4. Boolean Blocks ⬡ — The True/False Answerers¶

Shape: Hexagon (six-sided, like a nut!)

Job: Answer a yes/no question — gives either true or false.

Where they go: Inside hexagonal (pointy) slots in other blocks. Usually in if, repeat until, or wait until blocks.

Examples: - touching [mouse-pointer v]? 🔷 — true if touching mouse - key [space] pressed? 🔷 — true if space held down - < 5 > 3 🟢 — true (5 is greater than 3) - = 10 10 🟢 — true (10 equals 10) - < [score] > 100 🔴 — true if score > 100

⬡ Boolean = Yes/No

Think of Boolean blocks as questions that Scratch answers with YES (true) or NO (false).

if <touching [edge v]?> then
    bounce
end
     ↑
Boolean block fits here

5. Cap Blocks 🛑 — The Script Stoppers¶

Shape: Flat top, rounded bottom (like a cap on a bottle!)

Job: End a script — stop this script, or stop ALL scripts.

Where they go: ONLY at the very bottom of a script stack. Nothing can go below them!

Examples: - stop [this script v] 🟠 — stops just this stack - stop [all v] 🟠 — stops EVERYTHING (like hitting the stop sign) - stop [other scripts in sprite v] 🟠 — stops other stacks in same sprite

🛑 Cap = The End

Nothing runs after a cap block. It's like a period at the end of a sentence — the script is DONE.

Block Shapes Quick Reference¶

Shape	Name	Starts Script?	Does Action?	Gives Value?	True/False?	Ends Script?	Where It Goes
🎩	Hat	✅ YES	No	No	No	No	Top only
🧱	Stack	No	✅ YES	No	No	No	Middle
📊	Reporter	No	No	✅ YES	No	No	Inside white slots
⬡	Boolean	No	No	No	✅ YES/NO	No	Inside hexagonal slots
🛑	Cap	No	No	No	No	✅ YES	Bottom only

Diagram: Block Shape Flow¶

Block Shape Flow

Type: diagram sim-id: block-shape-flow
Library: p5.js
Status: Specified

Purpose: Show how block shapes fit together in a complete script

Components to show: - A complete script with all 5 shapes in correct positions: 1. Hat block at top: when green flag clicked 2. Stack blocks in middle: move 10 steps, turn 15 degrees, wait 1 secs 3. Reporter blocks inside slots: go to x: (x position) y: (y position) 4. Boolean block inside if: if <touching [edge v]?> then 5. Cap block at bottom: stop [this script v] - Arrows showing valid connections: - Hat → Stack ✅ - Stack → Stack ✅ - Reporter → White slot ✅ - Boolean → Hex slot ✅ - Stack → Cap ✅ - Red X showing invalid connections: - Stack → Hat ❌ - Reporter standing alone ❌ - Cap in middle ❌

Style: Annotated script with color-coded connection lines (green=valid, red=invalid)

Labels: - "Hat starts the script" - "Stacks do actions in order" - "Reporters fill white slots" - "Booleans fill hex slots" - "Cap ends the script"

Color scheme: Match actual Scratch block colors

The Script Area — Your Workbench¶

The script area is the big gray space in the middle where you build scripts.

Script Area Features¶

Feature	What It Does
Gray background	Your canvas — drag blocks here
Grid lines	Help align blocks neatly
Multiple scripts	You can have many separate stacks
Right-click menu	Duplicate, delete, add comment, clean up
Zoom controls	Bottom-right: + / - / 100%

Useful Right-Click Tricks¶

Action	How To
Duplicate stack	Right-click top block → "Duplicate"
Delete stack	Right-click top block → "Delete"
Add comment	Right-click block → "Add comment" (yellow sticky note!)
Clean up	Right-click empty space → "Clean up" (aligns blocks neatly)
Block help	Right-click block → "Help" (shows what it does!)

💬 Comments Are Your Friends!

Right-click any block → "Add comment" to leave notes for yourself or others. Great for remembering what a tricky section does!

Costume Center — The Secret Pivot Point¶

Every costume has a center point (crosshair) that determines:

Where the sprite rotates around
Where the costume attaches to the sprite's position
What "touching" checks use as the contact point

Setting the Costume Center¶

Go to Costumes tab
Select a costume
Click the crosshair tool (looks like a + target)
Click where you want the center

Center Point Tips¶

Sprite Type	Best Center Location
Walking character	Feet (bottom middle) — so feet stay on ground
Spinning object	Exact geometric center — spins smoothly
Car/vehicle	Bottom center of wheels — drives on ground
Projectile (bullet)	Tip/front — hits target from front

🎯 Test Your Center!

After setting the center, go to Code tab and add:

when green flag clicked forever turn (15) degrees wait (0.1) secs end

Watch how it spins — if it wobbles, adjust the center!

Sound Blocks — Making Noise!¶

The Sound category (🩷 pink) lets you add audio to your projects.

Key Sound Blocks¶

Block	What It Does	When to Use
`play sound [pop v] until done`	Plays sound, waits for it to finish	Dialogue, effects that must sync
`start sound [pop v]`	Starts sound, continues immediately	Background music, overlapping effects
`stop all sounds`	Stops everything playing	Scene changes, game over
`change pitch effect by (10)`	Higher/lower pitch	Chipmunk voice, slow-mo
`change pan left/right by (10)`	Move sound left/right	3D audio, stereo
`clear sound effects`	Reset pitch/pan	Cleanup
`set volume to (100%)`	Master volume	Menu settings
`change volume by (-10)`	Adjust volume	Fade in/out

Play Until Done vs. Start Sound¶

Block	Behavior	Use For
`play sound [pop] until done`	Waits for sound to finish before next block	Dialogue, sound effects that must complete
`start sound [pop]`	Continues immediately — sound plays in background	Background music, rapid-fire effects

🎵 Background Music + Sound Effects

when green flag clicked start sound [background-music v] // Music plays continuously forever if <key [space v] pressed?> then start sound [jump v] // Jump sound overlaps music change y by (50) wait (0.3) secs change y by (-50) end end

Recording Your Own Sounds!¶

Click Sounds tab
Click Choose a Sound 🎵
Click Record (🔴 microphone icon)
Allow microphone permission
Record your sound (clap, voice, instrument)
Click Stop ⏹️
Trim if needed, then Save

🎤 Sound Ideas

Record your own jump sound (say "boing!")
Record character voices for story games
Record real-world sounds (door creak, coin chime)

Adding Extensions — Superpowers for Scratch!¶

Extensions add extra blocks to Scratch — like adding new tools to your toolbox!

How to Add an Extension¶

Click the Extensions button (🧩 puzzle piece) at bottom-left of blocks palette
Browse or search for an extension
Click Add — new category appears in palette!

Built-In Extensions¶

Extension	Category Color	What It Adds
Pen	🟢 Green	Draw lines, shapes, art with code
Video Sensing	🟣 Purple	Use camera for motion detection
Text to Speech	🩷 Pink	Make sprites talk with synthetic voices
Translate	🔵 Blue	Translate text to other languages
Makey Makey	🟠 Orange	Physical controller input
micro:bit	🔵 Blue	BBC micro:bit hardware control
LEGO® Education	🟡 Yellow	LEGO SPIKE Prime, WeDo 2.0 robots
Go Direct	🟢 Green	Vernier science sensors

Pen Extension — Draw With Code!¶

The Pen is one of the most fun extensions — it turns your sprite into a drawing tool!

Pen Blocks¶

Block	What It Does
`pen down`	Start drawing (leaves trail)
`pen up`	Stop drawing
`erase all`	Clear all pen marks
`set pen color to [color]`	Change drawing color
`change pen color by (10)`	Cycle through colors
`set pen size to (5)`	Thickness of line
`change pen size by (5)`	Thicker/thinner
`stamp`	Leave a copy of costume as drawing

🎨 Draw a Square

when green flag clicked erase all pen down repeat (4) move (100) steps turn right (90) degrees end pen up

🌈 Rainbow Pen Trick

when green flag clicked erase all pen down set pen size to (10) repeat (360) move (5) steps turn right (1) degrees change pen [color v] by (1) end pen up

Video Sensing — Camera Magic!¶

Video Sensing uses your webcam to detect motion — like a motion sensor!

Video Sensing Blocks¶

Block	What It Does
`turn video [on v]`	Start/stop camera
`video [on v] on [stage v]`	Show/hide video on stage
`video transparency (50)`	How see-through video is
`video [motion v] on [this sprite v]`	Amount of motion detected (0-100)
`when video [motion] > (50)`	Hat block: triggers when motion detected

📷 Motion-Controlled Game

when green flag clicked turn video [on v] set video transparency to (50) forever if <(video [motion v] on [this sprite v]) > (30)> then change [color v] effect by (10) play sound [pop v] end end

Text to Speech — Talking Sprites!¶

Text to Speech makes sprites talk with synthetic voices — no recording needed!

Text to Speech Blocks¶

Block	What It Does
`speak [Hello!]`	Speaks text immediately
`speak [Hello!] and wait`	Speaks, waits for finish
`set voice to [alto v]`	Choose voice (alto, tenor, soprano, etc.)
`set language to [English v]`	Language (English, Spanish, French, etc.)

🗣️ Talking Character

when green flag clicked set voice to [tenor v] set language to [English v] speak [Welcome to my game!] and wait speak [Press space to jump!]

Translate — Speak Many Languages!¶

Translate converts text between languages instantly.

Translate Blocks¶

Block	What It Does
`translate [Hello] to [Spanish v]`	Reporter: gives translated text
`language [Spanish v]`	Reporter: language code

🌍 Multilingual Greeting

when green flag clicked set language to [Spanish v] speak (translate [Hello, friend!] to [Spanish v]) and wait

The Backpack — Your Portable Toolbox!¶

The Backpack (🎒 icon at bottom of sidebar) lets you save blocks, sprites, costumes, and sounds to use in OTHER projects!

What You Can Store¶

Item	How to Store
Scripts/blocks	Drag stack to backpack
Sprites	Drag sprite from sprite pane
Costumes	Drag costume from costumes list
Sounds	Drag sound from sounds list

How to Use the Backpack¶

Action	How To
Open backpack	Click 🎒 icon (bottom-left sidebar)
Save to backpack	Drag item TO backpack
Use from backpack	Drag item FROM backpack to project
Delete from backpack	Right-click in backpack → Delete

🎒 Backpack = Reuse Superpower!

Build a perfect jumping script once → save to backpack → use in ALL your platformer games!

Build a cool enemy AI → backpack → drop into next game!

Summary¶

In this chapter, you learned:

✅ 5 block shapes — Hat (start), Stack (do), Reporter (give value), Boolean (true/false), Cap (stop)
✅ Where each shape goes — Top, middle, inside slots, bottom
✅ Script area features — Right-click tricks, comments, clean up
✅ Costume center — The pivot point for rotation and touching
✅ Sound blocks — Play/start sound, pitch, volume, recording
✅ Extensions — Pen, Video Sensing, Text to Speech, Translate, and more
✅ Pen extension — Draw with code (pen down/up, color, size, stamp)
✅ Video Sensing — Camera motion detection for interactive games
✅ Text to Speech — Synthetic voices in many languages
✅ Translate — Instant translation between languages
✅ Backpack — Save and reuse blocks/sprites across projects

Key Terms to Remember¶

Term	Definition
Hat Block	Starts a script (rounded top)
Stack Block	Does an action, snaps in middle
Reporter Block	Gives a value, fits in white slots
Boolean Block	Answers true/false, fits in hex slots
Cap Block	Ends a script (rounded bottom)
Script Area	Gray workspace where you build scripts
Costume Center	Pivot point for rotation and touching
Extension	Extra blocks added via 🧩 button
Pen Extension	Drawing with code (trails, stamping)
Video Sensing	Camera-based motion detection
Text to Speech	Synthetic voice from text
Translate	Convert text between languages
Backpack	Cross-project storage (🎒 icon)

Try It Yourself! 🎯¶

Challenge 1: Build a script using all 5 block shapes in correct order (Hat → Stacks → Reporters/Booleans → Cap)

Challenge 2: Set the costume center to the feet of a walking character, then make it spin — does it wobble?

Challenge 3: Add the Pen extension and draw a spirograph (hint: repeat 360, move a little, turn 1 degree, change color)

Challenge 4: Record a custom jump sound and use start sound in a platformer

Challenge 5: Add Text to Speech and make a sprite introduce itself in 3 different voices

Challenge 6: Open the Backpack, save your favorite script, then create a NEW project and drag it from the backpack

What's Next?¶

In Chapter 4, you'll dive into Events, Sequences, and First Scripts. You'll learn how to chain events together, build your first complete interactive project, and understand the flow of a Scratch program from start to finish!

→ Next Chapter: Events, Sequences, and First Scripts