Click image to open full size
Scratch Block Programming Reference Cheat Sheet
A printable reference covering Scratch event, motion, looks, sound, control, sensing, operator, variable, and custom blocks for grades 3-8.
Related Tools
Related Labs
Related Worksheets
Related Infographics
Scratch block programming helps students build animations, games, stories, and simulations by snapping code blocks together. This cheat sheet gives grades 3-8 a clear reference for the blocks they use most often. It helps students remember what each block type does and how blocks work together in a program. A clean reference page also makes debugging and planning projects easier. The most important ideas are events, sequences, loops, conditionals, variables, and messages. Events start scripts, such as when green flag clicked or when this sprite clicked. Control blocks repeat actions or make choices, such as repeat 10, forever, if then, and if then else. Variables store changing information, while operators compare values or combine text and numbers.
Key Facts
- An event block such as when green flag clicked starts a script when a specific action happens.
- A sequence runs blocks in order from top to bottom, so block order can change the result.
- The block move 10 steps changes a sprite's position in the direction it is facing.
- The block repeat 10 runs the blocks inside it exactly 10 times.
- The block forever repeats the blocks inside it until the program stops.
- The block if condition then runs its inside blocks only when the condition is true.
- A variable such as score can store a value, and change score by 1 increases that value by 1.
- The block broadcast message sends a signal that can start scripts with when I receive message.
Vocabulary
- Sprite
- A sprite is a character or object in a Scratch project that can run scripts and appear on the stage.
- Stage
- The stage is the area where sprites move, talk, change costumes, and show the project.
- Script
- A script is a stack of connected blocks that tells a sprite or the stage what to do.
- Event
- An event is an action, such as clicking the green flag, that starts a script.
- Loop
- A loop is a control block that repeats one or more blocks a set number of times or forever.
- Variable
- A variable is a named storage place for information that can change while a program runs.
Common Mistakes to Avoid
- Putting blocks in the wrong order is a mistake because Scratch runs a script from top to bottom. Place setup blocks, such as set score to 0, before blocks that use the value.
- Using forever when repeat 10 is needed is a mistake because forever never stops on its own. Use a counted loop when the action should happen a specific number of times.
- Forgetting an event block is a mistake because a script with no starter block may not run when expected. Add an event such as when green flag clicked or when this sprite clicked.
- Changing a variable before creating or resetting it is a mistake because the value may carry over from an earlier run. Set variables such as score or timer to a starting value at the beginning.
- Using if then when if then else is needed is a mistake because the program only handles the true case. Use if then else when the sprite needs one action for true and a different action for false.
Practice Questions
- 1 A sprite starts at x = 0. It runs move 10 steps five times while facing right. What is its new x-position?
- 2 A game starts with set score to 0. Then the player collects 7 coins, and each coin runs change score by 1. What is the final score?
- 3 Write a short Scratch plan using blocks that makes a sprite say Hello for 2 seconds when the green flag is clicked, then move 20 steps.
- 4 Why is a broadcast message useful when one sprite needs to make another sprite start an action at the same time?