1. Review and demonstration (2+ minutes):
Begin by asking coders to talk with a neighbor for 30 seconds about something they learned last time; assess for general understanding of the practices and concepts from the previous project.

Explain that today we are going to simulate spray painting by using a new pen block. Display and demonstrate the sample project (or your own remixed version).

Video: Project Preview (0:58)
Video: Lesson pacing (1:48)

This can include a full class demonstration or guided exploration in small groups or individually. For small group and individual explorations, you can use the videos and quick reference guides embedded within this lesson, and focus on facilitating 1-on-1 throughout the process.

Example review discussion questions:

• What’s something new you learned last time you coded?
  • Is there a new block or word you learned?
• What’s something you want to know more about?
• What’s something you could add or change to your previous project?
• What’s something that was easy/difficult about your previous project?

2. Discuss (10+ minutes):
Have coders talk with each other about how they might create a project like the one demonstrated. If coders are unsure, and the discussion questions aren’t helping, you can model thought processes: “I noticed the sprite moved around, so I think they used a motion block. What motion block(s) might be in the code? What else did you notice?” Another approach might be to wonder out loud by thinking aloud different algorithms and testing them out, next asking coders “what do you wonder about or want to try?”

Discuss different examples of street art from your community and online; see this website by Google for potential examples. Engage in a discussion on when street art and spray painting is legal (e.g., commissioned artwork or when you own the property) and when it is illegal (e.g., spray painting without permission).

After the discussion, coders will begin working on their project as a class, in small groups, or at their own pace.

Resource: Google’s Street Art website

Note: Discussions might include full class or small groups, or individual responses to discussion prompts. These discussions which ask coders to predict how a project might work, or think through how to create a project, are important aspects of learning to code. Not only does this process help coders think logically and creatively, but it does so without giving away the answer.

Example discussion questions:

• What would we need to know to make something like this in Scratch?
• What kind of blocks might we use?
• What else could you add or change in a project like this?
• What code from our previous projects might we use in a project like this?
• When is street art legal?
  • What permissions must you have before creating street art?

4. Simulate spray painting (10+ minutes):
1+ minute review and discussion
Review how to add the pen blocks from the extensions. Display the pen blocks for the class and ask coders to discuss what blocks were used in the example project (the stamp and erase all blocks).

7+ reverse engineering
Ask coders to figure out how to simulate spray painting using the Spray paint sprite in the remix project.

Every couple of minutes, give one of the following hints:

• You will need to have the sprite forever follow the mouse
• You will need to stamp when the mouse is down (clicked)
• You will need to point in a random direction to vary the spray pattern
• You will need to erase all to reset the program

2+ minute demonstration and discussion
Demonstrate how to make the sprite forever follow the mouse and indicate we can use an if block to check if the mouse is down. When it is, we will stamp a copy of the sprite on the backdrop. To vary the spray pattern, place a pick random 0 to 360 block inside of a point in direction block and put that either above or below the stamp block. Finally, demonstrate that the stamps stay on the screen when the green flag is clicked, so we want to add an erase all block to reset the backdrop each time the program is run.

Video: Simulate spray painting (3:59)
Quick reference guide: Click here

Facilitation Suggestion: Some coders may not thrive in inquiry based approaches to learning, so we can encourage them to use the Tutorials to get more ideas for their projects; however, we may need to remind coders the suggestions provided by Scratch are not specific to our projects, so it may create some unwanted results unless the code is modified to match our own intentions.

A note on using the “Coder Resources” with your class: Young coders may need a demonstration (and semi-frequent friendly reminders) for how to navigate a browser with multiple tabs. The reason why is because kids will have at least three tabs open while working on a project: 1) a tab for Scratch, 2) a tab for the Coder Resources walkthrough, and 3) a tab for the video/visual walkthrough for each step in the Coder Resources document. Demonstrate how to navigate between these three tabs and point out that coders will close the video/visual walkthrough once they complete that particular step of a project and open a new tab for the next step or extension. Although this may seem obvious for many adults, we recommend doing this demonstration the first time kids use the Coder Resources and as friendly reminders when needed.

5. Create user controls (10+ minutes)
1 minute challenge introduction
Ask the class what kind of user controls we could add to a project like this (e.g., changing the spray paint’s size or color, erasing the screen, showing or hiding the sprite that follows the mouse, changing the spray paint sprite to a different costume, etc.).

9+ minute project work and 1-on-1 facilitating
Give the class some time to figure out which kind of interaction they would like to incorporate (e.g., keyboard or buttons). Encourage peers to work together and facilitate by asking guiding questions or having coders review their previous projects.

Video: Create user controls (3:22)
Quick reference guide: Click here

Facilitation Suggestion: Some coders may not thrive in inquiry based approaches to learning, so we can encourage them to use the Tutorials to get more ideas for their projects; however, we may need to remind coders the suggestions provided by Scratch are not specific to our projects, so it may create some unwanted results unless the code is modified to match our own intentions.

6. Experiment with more blocks (20+ minutes):
15+ minute coding time and 1-on-1 facilitating
Give time for coders to experiment with adding more code to create street art. Encourage coders to use My Blocks to create functions for each chunk of code.

5+ minute collaborative demonstration
When coders have had some time to explore using the blocks, ask coders to share with neighbors, small groups, or the entire class how they created street art with code. Encourage coders to compare their code with a neighbor to find similarities and differences.

Video: Experiment with more blocks (1:45)
Quick reference guide: Click here

Suggested questions:

• What other blocks can change the appearance of the sprite that is stamped on the backdrop?
  • What other looks blocks and motion blocks could you use?
• Are there are other pen block that you could use to create street art?
  • How do you think you could use this pen block (point to a block) to create street art?

Facilitation Suggestion: Some coders may not thrive in inquiry based approaches to learning, so we can encourage them to use the Tutorials to get more ideas for their projects; however, we may need to remind coders the suggestions provided by Scratch are not specific to our projects, so it may create some unwanted results unless the code is modified to match our own intentions.