A Teacher’s Guide to Scratch: Lesson 7

August 3, 2015 by wendy

Scratch Backdrop Project
cat and dog!!!!!!! by crazydog6000 on Scratch

In Lesson 6, we saw how we can use timing and messaging to synchronize sprites. This week, we continue to investigate how we can coordinate sprites with backdrops!

Lesson 7: The Stage

Why might it be useful to be able to coordinate the stage, or backdrops, with sprites? Can your students think of some examples?

What is the stage?

Suppose we want to add a start screen to one of our projects. Take, for example, the joke project that we made last week. We can remix the project so that when the start screen is clicked, the joke begins.

Show your students that they can add new backdrops by clicking on the Stage to the left of the Sprites area and selecting the Backdrops tab. The stage can have multiple backdrops just like sprites can have multiple costumes.

Click back to the Scripts tab. We can write code for the stage just like we can write code for sprites except that the stage has different code blocks. For example, the stage doesn’t have any motion blocks, but it does have looks blocks like “switch backdrop to…” and “next backdrop”.

Adding a start screen

Joke Project with Start Screen
Knock Knock Joke with Start Screen by marshmallowcoding on Scratch

Work together as a class or have your students work individually to add a start screen to an existing project. Choose any project or try our Knock Knock Joke with Start Screen project above that has notes for you to follow along! If your students worked individually, ask for a few volunteers to share their backdrops when they’re finished.

Polya’s problem solving tips

By adding timing, messaging, and backdrop changes, we’re adding a lot of complexity to our projects, which can also add glitches or bugs. Trying to fix these bugs can be frustrating. Here are some problem solving tips that you can share with your students:

  1. Understand the problem.
    • Can you explain the problem in your own words?
    • Can you draw a picture?
    • What do you already know?
    • What do you need to find out?

  2. Make a plan.
    • Have you solved a problem like this before?
    • Can you break the problem down into smaller pieces?
    • Is there something that you can test?

  3. Do it.
    • Carry out your plan.
    • Execute each step carefully.

  4. Check your work.
    • Did your solution fix the problem?
    • Could you have done it differently?
    • Can you use your solution to solve other problems?

Project time

For the rest of the class, your students can keep working on their design projects. Challenge them to incorporate multiple backdrops!

A Teacher’s Guide to Scratch: Lesson 6

July 28, 2015 by wendy

Scratch Messaging Project
Gobo is getting what he wished for! by pugs22 on Scratch

At this point, your students might be asking, “How can one sprite tell another sprite to do something?” Let’s find out!

Lesson 6: Knock, Knock

Give some examples of features that your students might want to have in their design projects. Maybe they want a sprite to appear or disappear when another sprite says something. We can do this!

Real-life scripts

Script 1 without timing or messaging
Script for your first volunteer

Script 2 without timing or messaging
Script for your second volunteer

Start with some role-playing. In Scratch, show the script that’s above on the left to your students. Ask for a volunteer to perform the script. Reveal the script for another sprite that’s on the right. Ask for another volunteer, and have both volunteers perform the scripts at the same time. What’s the problem? Our sprites talk over each other! We need to coordinate them, but how?

Timing using wait blocks

Script 1 with timing
First script with timing

Script 2 with timing
Second script with timing

We can tell sprites to wait for each other by using wait blocks. How can we use wait blocks to fix our problem? Work as a class to come up with a solution and have your performers test it. Your solution should look like the scripts above.

Messaging using broadcast and receive blocks

Script 1 with messaging
First script with messaging

Script 2 with messaging
Second script with messaging

Wait blocks worked in this scenario because we knew how long to wait, but what if we didn’t know how long to wait? Is there another way?

Introduce broadcast and receive blocks. In Scratch, sprites can send invisible messages like radio signals to other sprites. Other sprites can choose to do something when they receive certain messages.

Revisit your solution with the wait blocks, and as a group, try to replace them with broadcast and receive blocks. Your solution should look like the scripts above. Run your scripts to make sure they work.

Lightning round

Give your students 10 minutes to create a joke project. They can remix an existing project or start a brand new one. At the end of 10 minutes, ask 5 volunteers to share their jokes with the class.

Project time

For the remainder of the class, students can continue to work on their design projects. Encourage them to incorporate timing or messaging into their designs!

A Teacher’s Guide to Scratch: Lesson 5

July 13, 2015 by wendy

Scratch Design Project
Reduce Reuse Recycle by pugs22 on Scratch

Congratulations! You’re halfway through our Coding for Kids program! We’ve learned how to sequence instructions to build complex behaviours, how to use events to make interactive programs, and how to use loops to create animations and music. In this lesson, students have the chance to design their own projects.

Lesson 5: Design Project

An open-ended design project is an opportunity for students to not only develop greater fluency in concepts such as events and loops, but also design a project that’s relevant and meaningful to them. What topics are your students most interested in? What types of projects would they like to make?

Project Overview

Explain to your students that today, they’ll be coming up with their own Scratch projects. They can choose to work individually or in pairs. They’ll continue to work on their projects over the next few lessons. Then on the last day, they’ll present their projects to the class!

Today, their job is to brainstorm, come up with an idea, make a plan, and to gather feedback. If they finish early, they can start working on their projects.

Getting started

I Love Scratch
I Love Scratch by Blackhawks215

Scratch Events Project
Where are my friends? by flyingcows79

Scratch Music Project
Let’s make music by marshmallowcoding

Scratch Dance Party
joe’s party by coderlover360

Remind your students by reviewing past projects that they’ve learned a lot. Now that it’s their turn to design a project, what will they create? Start a discussion with your students about topics that interest them and the types of projects that they would like to make.

Give them the option to build on an existing project or to create a brand new one. Also remind them that it’s okay if there’s a part of the project that they don’t know how to make yet. We’ll still be learning new concepts over the next few lessons, and they can also research on their own!

Making a plan

Give your students time to explore and brainstorm. Perhaps they can add projects that inspire them into their own Scratch studios. Encourage them to sketch their ideas, and to write down any questions and how they might find the answers.

Gathering feedback

Once your students are ready, ask them to share their project plans with other students and to gather at least 3 suggestions. If there’s time remaining, students can start working on their projects, and at the end of class, ask for a few volunteers to share their progress.

A Teacher’s Guide to Scratch: Lesson 4

July 6, 2015 by wendy

Scratch Dance Party
joe’s party by coderlover360 on Scratch

We continue to explore loops, music, and animation by building dance parties with our favourite songs!

Lesson 4: Dance Party

Last week, we played with repeat loops to animate sprites and make music. How are repeat loops helpful? This week, we’re experimenting with another type of loop called the forever loop. Can your students guess what a forever loop is for?

Dance, Dance, Dance

Dance Party
Dance Party by blockstobots

Dance Starter Ideas
Dance Starter ideas by chrisg

Scratch Cat and Nano Hip-Hop Project
Scratch Cat and Nano Hip-Hop Project by ricarose

Start the lesson by looking at some dance party examples like the ones above. How did each sprite have so many different looks? In Scratch, we need costumes!

Costumes in Scratch

Create a new project and make sure that Scratch Cat is selected. Click on the Costumes tab next to the Scripts tab. Notice that even Scratch Cat has two different poses or costumes: costume1 looks like Scratch Cat is walking and costume2 looks like Scratch Cat is running. If you click between the two, Scratch Cat starts to animate, but how do we animate using code?

Making sprites dance!

Making Sprites Dance
Animating sprites using forever blocks and costume blocks

By combining forever blocks with costume blocks, we can make sprites dance. Choose a sprite with multiple costumes, and then demonstrate different ways to animate the sprite:

  • Drag the “next costume” block and “wait 1 secs” block into a forever block.
  • Snap a series of “switch costume to…” and “wait 1 secs” blocks inside a forever block.

Don’t forget to show students that they can also paint new costumes to create their own animations.

Adding a favourite song

Ask your students to think of a favourite song to add to their dance party. Follow these steps to add a song from a YouTube video into a Scratch project:

  1. Go to YouTube and choose a video.
  2. Copy the URL.
  3. Go to youtube-mp3.org.
  4. Paste the URL into the box.
  5. Click on Convert Video.
  6. Click on Download.
  7. Go to your Scratch project.
  8. Click on the Sounds tab.
  9. Click on the “Upload sound from file” icon.
  10. Select your downloaded song file.
  11. Click on the Scripts tab.
  12. Click on Sound.
  13. Click the arrow on the “play sound … until done” block to choose your song.
  14. Drag the “play sound … until done” block into a forever block.

Building a dance party

Give students time to find their favourite song and to explore different dance parties. Here are a couple of places to start: Dance, Dance, Dance Studio and Scratch Day Dance Party.

They can also watch the Make your sprite dance video or try the Dance, Dance, Dance tutorial by clicking on “Tips” in the Scratch editor.

Encourage students to create their own project or to remix an existing project. Challenge them to animate the backdrop. Have your students add their dance parties to the class studio and gather feedback from at least three other students.

A Teacher’s Guide to Scratch: Lesson 3

June 30, 2015 by wendy

Scratch Music Project
Let’s make music by marshmallowcoding on Scratch

Unplugged activities are a great way to demonstrate new concepts. This week, we’re Getting Loopy with an unplugged activity by Code.org!

Lesson 3: Getting Loopy

Through dance, students are introduced to the concept of loops, or in other words, actions that repeat over and over again. Why are loops important in computer programming? How can we use loops to create animations and music?

Loops unplugged

Unplugged-Getting Loopy by Code.org on YouTube

First, play the Getting Loopy video from Code.org to introduce students to the concept of loops and the upcoming activity. The music, dancing, and light suits in the video will definitely get them excited!

Warm up

Review the definition of a loop. A loop is a set of actions that repeat over and over again. Before starting the dance, warm up with the Repeat After Me activity to demonstrate why loops are important in computer programming.


Uptown Funk featuring Bruno Mars by Mark Ronson on YouTube

Now that everyone is warmed up, let’s dance! Choose an upbeat song that your students will enjoy, like Uptown Funk featuring Bruno Mars. Project the dance routine, The Iteration, onto a screen so that everyone can follow along. Practice the routine once slowly without music. Then perform the routine at full speed with music!

Loops in Scratch

In Scratch, one way to make a loop is with the repeat block. Demonstrate different ways to create an animation or song using repeat blocks:

  • Drag the “move 10 steps” block into a repeat block
  • Drag one of the turn blocks into a repeat block
  • Drag the “change color effect by 25” block into a repeat block
  • Drag the “change size by 10” block into a repeat block
  • Drag the “play drum” or “play note” block into a repeat block
  • Snap two repeat blocks together
  • Place a repeat block inside another repeat block

Animation, music, or both

After some experimentation, challenge students to create an animation or music project using loops. They can remix an existing animation or music project, create their own, or attempt to combine the two! Once everyone is ready, have students walk around the classroom to see everyone’s creations.