UNIT 4

GAMES

YOU ARE HERE WHAT’S INCLUDED

DREAM GAME LIST
4 STARTER GAMES
SCORE
0 1 2 3 5 6 EXTENSIONS
INTERACTIONS
DEBUG IT!
UNIT 4
OVERVIEW
THE
THE “BIG IDEA”IDEA”
“BIG
Personalization is an important guiding principle in the design of the creative computing experience. By “personalization”, we
mean both connecting to personal interests and acknowledging that personal interests can vary considerably. There are many
ways of knowing and doing – and exploring these multiple ways can help support interest, motivation, and persistence among
young learners. In this unit, learners explore some of the advanced concepts and challenging problems associated with game
design. An advanced concept or challenging problem can be made more accessible if rooted in activities that are personally
meaningful. As an example of the power of context, we turn to a story shared by Mitch Resnick – the director of the Scratch
project at MIT.
A few years ago I was at one of our Computer Clubhouse after
school centers and I saw a 13-year-old boy working on creating his
own game. He was able to control a character, in this case, a fish. He
wanted the game to keep track of the score, so you could see how
many little fish had been eaten by the big fish, but he didn’t know
how.

I saw this as an opportunity to introduce the idea of variables. I

showed this to him and he immediately saw how he could use this
block to keep track of how many fish had been eaten in his game. He
took the block and put it in the script right where the big fish eats
the little fish. He quickly tried it. Sure enough, every time the big
fish ate a little fish, the score goes up by 1.

I think that he really got a deep understanding of variables because

he really wanted to make use of it. That's one of our overall goals of
Scratch. It's not just about variables, but for all types of concepts. We
see that kids get a much deeper understanding of the concepts they
learn when they are making use of the concepts in a meaningful KEY WORDS, CONCEPTS, & PRACTICES
and motivating way.
+ abstracting and modularizing + sensing
+ conditionals + feedback fair
LEARNING OBJECTIVES + operators + arcade day
Students will: + data + puzzle jar
+ variables and lists + brain dump
+ be introduced to the computational concepts of
conditionals, operators, and data (variables and lists)
NOTES
+ become more familiar with the computational practices of
experimenting and iterating, testing and debugging, reusing + Many new concepts are explored in this unit, so we’ve
and remixing, and abstracting and modularizing by building included added support in the form of example project
and extending a self-directed maze, pong, or scrolling game studios, new programming puzzles for extra practice, and
project starter game projects that we encourage you to remix
+ identify and understand common game mechanics and reuse as needed.
 CHOOSE YOUR OWN ADVENTURE

In this unit, learners will become game designers and

experience creating their own game project. Guided by the
activities in this unit, students will be introduced to game
mechanics and game development while building
understandings of computational concepts (conditionals,
operators, data) and computational practices (abstracting
and modularizing).

You could get students started on their game projects with

the Starter Games activity and then support further
development through other activities. From learning
common game mechanics such as keeping score and
side-scrolling, to the creation of multiplayer games
(e.g., Pong), Unit 4 activities offer students multiple
opportunities to practice game development.

POSSIBLE PATH

SESSION 1 SESSIONS 1 - 5 SESSION 2 SESSION 3 SESSION 4 SESSION 5

DREAM GAME STARTER SCORE EXTENSIONS INTERACTIONS DEBUG IT!

LIST GAMES

What do all games How can you use How can you add What are different Tackle nine Scratch Help!
have in common? Scratch to build an score to a game ways of extending programming Can you debug
interactive game? using variables? and increasing puzzles. these five Scratch
difficulty in a game? programs?
UNIT 4 ACTIVITY
DREAM GAME OBJECTIVES
By completing this activity, students will:

LIST SUGGESTED TIME

+ identify common design elements of games

15–30 MINUTES

ACTIVITY DESCRIPTION RESOURCES

❑ Divide students into small groups of 2-3 people. ❑ paper to write down game design elements
❑ things to sketch with (pencils, pens, markers, etc.)
❑ In their small groups, ask students to generate a list of
games that they enjoy playing. They can compose the
list using their design journals or a sheet of paper. We REFLECTION PROMPTS
suggest facilitating the brain dump brainstorming
activity: give students a short time period (1-2
+ Make a list of your favorite games.
minutes) to write down as many games as they can.
+ What do the games have in common?
Then, have students narrow down their favorites from
+ What features of their design make them a game?
the brain dump list.
+ Create a list of design elements for your dream
❑ After a few minutes, ask groups about their list of game.
games:
What do the games have in common?
What features of their design make them a game? REVIEWING STUDENT WORK
❑ Facilitate a class discussion about what characteristics
make up a game and generate a class list of common + Do the dream game lists include features of games?
game mechanics. Next, ask students to imagine their + What design elements are similar or different from
dream game and write a list of design elements for the class group list?
that game. + What do the lists tell you about the kinds of games
and the types of play your students enjoy?
❑ Invite students to share their dream game lists in their
small groups or critique groups (see Unit 0 Critique
Group activity) to get feedback and suggestions.

NOTES NOTES TO SELF

+ Invite students to refer back to this dream game list ❑ _______________________

while programming games in other Unit 4 activities.
❑ _______________________
❑ _______________________
❑ _______________________
 UNIT 4 REFLECTION
NAME:

DREAM GAME
LIST RESPOND TO THE FOLLOWING REFLECTION PROMPTS
USING THE SPACE PROVIDED BELOW OR IN YOUR

REFLECTIONS
DESIGN JOURNAL.

+ Make a list of your favorite games.

+ What do the games have in common?

+ What features of their design make them a game?

+ Create a list of design elements for your dream game.

UNIT 4 ACTIVITY
STARTER GAMES OBJECTIVES
By completing this activity, students will:
+ develop greater fluency with computational
concepts (conditionals, operators, data) and
practices (experimenting and iterating, testing and
SUGGESTED TIME
debugging, reusing and remixing, abstracting and
45–60 MINUTES
modularizing) by working on a self-directed game
project

ACTIVITY DESCRIPTION RESOURCES

❑ In this activity, students will create a starter game ❑ Maze handout

project that can be revisited and extended during the ❑ Maze example starter project
Score, Extensions, and Interactions activities. http://scratch.mit.edu/projects/11414041
Optionally, show the Maze, Pong, and Scrolling ❑ Pong handout
example starter projects, and have the Maze, Pong, and ❑ Pong example starter project
Scrolling handouts available to guide students. http://scratch.mit.edu/projects/10128515
❑ Scrolling handout
❑ Choose one game project to facilitate as a class or let
❑ Scrolling example starter project
students choose which game they want to create:
http://scratch.mit.edu/projects/22162012
maze, pong, or scrolling. Give students time to start
❑ Games studio
building their games or let them remix one of the
http://scratch.mit.edu/studios/487504
starter projects.
❑ Encourage students to get feedback on their
games-in-progress. We suggest the feedback fair REFLECTION PROMPTS
activity: half of the students stay in their seats with
their projects open while the other half walks around + What was challenging about designing your game?
exploring projects, asking questions, and giving + What are you proud of?
feedback, then switch sides. Optionally, have students
add their final game projects to the Games studio or a
class studio.
REVIEWING STUDENT WORK
❑ Ask students to respond to the reflection prompts in
+ Do games include conditionals, operators, and data?
their design journals or in a group discussion.

NOTES NOTES TO SELF

+ To celebrate and share final game creations, we ❑ _______________________

recommend hosting an Arcade Day. Final game projects
are placed in presentation mode; students walk around ❑ _______________________
and play each other’s games.
+ The Scrolling game option introduces cloning. Help ❑ _______________________
students learn more about the cloning blocks with the ❑ _______________________
Cloning handout from Unit 5 Advanced Features.
 MAZE
HOW CAN YOU USE SCRATCH TO BUILD
AN INTERACTIVE GAME?

In this project, you will create a game. This

game includes interactions between sprites,
score, and levels. You move a sprite from the
start of a maze to the end without touching
the walls.

START HERE
❑ Draw a maze-like background and use different
colors for the walls and end-of-maze marker.
❑ Add a sprite.
❑ Make your game interactive!
These scripts give the player control over sprite movement in the
maze.

THINGS TO TRY
❑ Add multiple levels to your game! This can This tells your sprite where to begin
be done through the use of different and marks the start of the maze.
backdrops and using broadcast blocks to
trigger the next level. This tells the end-of-maze sprite
❑ Use the make a variable block to keep score! that players win when the ball
❑ Experiment with timer blocks to add new touches this sprite.
challenges to your maze!
This will cause your sprite to bounce off
the blue walls of the maze.

BLOCKS TO PLAY WITH FINISHED?

FINISHED?

+ Add your project to the

Games Studio:
http://scratch.mit.edu/studios
/487504
+ Swap games with a partner
and walk each other through
your creations.
 PONG
HOW CAN YOU USE SCRATCH TO BUILD
AN INTERACTIVE GAME?

In this project, you will create a game. This

game includes interactions between
sprites, score, and levels. The game is
similar to the classic game of pong, where
the goal is to keep the sprite from getting
past you.

START HERE
❑ Create two sprites: a paddle for the user to
control and a ball the user will be playing with.
❑ Make your paddle sprite interactive.
❑ Bring your game to life!

THINGS TO TRY
❑ How do you add difficulty to your game?
Creating different levels, using a timer, or
keeping score are a few examples of things
you could do.
❑ Experiment with changing the look of your Interacts with the walls
game by editing the backdrops! Interacts with the paddle
❑ Explore using different key presses to control
your sprites! These control the ball - if touching the paddle or a wall, it continues moving. If
touching red (meaning the ball moved past the paddle) the game ends.

FINISHED?
BLOCKS TO PLAY WITH FINISHED?
FINISHED?

+ Add your project to the

Games Studio:
http://scratch.mit.edu/studios
/487504
+ Swap games with a partner
and walk each other
through your creations.
 SCROLLING
HOW CAN YOU USE SCRATCH TO BUILD AN
INTERACTIVE GAME?

In this project, you will create a game. This game

includes interactions between sprites, score, and
levels. The game is similar to Flappy Bird, where
the goal is to keep an object from falling to the
ground or touching certain objects.

START HERE
❑ Create two sprites: one for the player to control Controls sprite movement

(helicopter) and one to avoid (gliding bars).

❑ Make the helicopter interactive.
❑ Bring your game to life by adding scripts to
make the gliding bars scroll across the stage!

THINGS TO TRY
This creates clones, which are used in the
Causes sprite to constantly fall downward
script below to make the bars scroll across
❑ How do you add difficulty to your game? the screen:
Creating different levels, using a timer, or
keeping score are a few examples of things
you could do.
❑ Experiment with changing the look of your
game by editing the backdrops!
❑ Explore using different key presses to control
your sprites!
Specifies when the game ends

FINISHED?
BLOCKS TO PLAY WITH FINISHED?

+ Add your project to the

Games Studio:
http://scratch.mit.edu/studios
/487504
+ Swap games with a partner
and walk each other
through your creations.
 UNIT 4 REFLECTION
STARTER
NAME:

GAMES RESPOND TO THE FOLLOWING REFLECTION PROMPTS

USING THE SPACE PROVIDED BELOW OR IN YOUR

REFLECTIONS
DESIGN JOURNAL.

+ What was challenging about designing your game?

+ What are you proud of?

UNIT 4 ACTIVITY
SCORE OBJECTIVES
By completing this activity, students will:
+ be able to describe what a variable is and why
variables are useful
SUGGESTED TIME
+ be introduced to the computational concept of
30–45 MINUTES data
+ experience remixing and reusing a project or part
of a project

ACTIVITY DESCRIPTION RESOURCES

❑ Optionally, explore the Fish Chomp starter project as a ❑ Score handout

group and have the Score handout available to guide ❑ Score examples studio
students. http://scratch.mit.edu/studios/218313
❑ Fish Chomp starter project
❑ Help students open the Fish Chomp starter project.
http://scratch.mit.edu/projects/10859244
Give students time to explore variables by remixing
❑ Fish Chomp remix studio
the Fish Chomp Starter Project to add score to the
http://scratch.mit.edu/studios/475615
game. Optionally, give students time to incorporate
score into their previously started maze, pong, or
scrolling game projects. REFLECTION PROMPTS
❑ Allow students to share their Fish Chomp remixes or
game projects with added score. We suggest the + How would you explain variables to someone else?
Design Demo activity: invite a few students to present + What are variables good for?
their projects to the group and demonstrate how they
implemented score using variables. Optionally, have REVIEWING STUDENT WORK
students add their remixes to the Fish Chomp Remix
studio or a class studio.
+ Can students explain what a variable is and what
❑ Ask students to think back on the design process by variables are good for?
responding to the reflection prompts in their design
journals or in a group discussion.

NOTES NOTES TO SELF

+ Encourage students to clarify their understanding of ❑ _______________________

variables by exploring code from sample projects in
the Score examples studio. ❑ _______________________
+ Variables are an important mathematical and
computational concept. Students are taught about ❑ _______________________
variables in their math and science classes, but many ❑ _______________________
students have a difficult time learning them. Games
are one way to make the usefulness of variables more
concrete.
 SCORE
HOW CAN YOU KEEP SCORE IN A
SCRATCH PROJECT?

Fish Chomp is a game where players try

to catch as many fish as they can by
guiding a sprite with the mouse. In this
activity, you will remix Fish Chomp by
adding a score with variables.

START HERE
❑ Go to the Fish Chomp project page:
http://scratch.mit.edu/projects/10859244
❑ Click on the Make a Variable button in the Data
category to create and name a variable for
score.
❑ Experiment with your new variable blocks to
incorporate score into your project!

E E LI NG
F
U C K?
ST E THIN
GS…
THES
THAT ’S O KAY! TRY FINISHED?

+ Add your project to the Fish Chomp

❑ Not sure how to work with variables? Check out this project for Remix studio:
more information: http://scratch.mit.edu/projects/2042755 http://scratch.mit.edu/studios/475615
❑ Or take a look at this video: http://youtu.be/uXq379XkhVw + Challenge yourself to do more! How can
❑ Explore and study code in games that use score to learn more you use score to add difficulty to your
about creating variables and incorporating score into a project. game design?
+ Find a game you are inspired by and
remix it!
 UNIT 4 REFLECTION
SCORE
NAME:

REFLECTIONS RESPOND TO THE FOLLOWING REFLECTION PROMPTS

USING THE SPACE PROVIDED BELOW OR IN YOUR
DESIGN JOURNAL.

+ How would you explain variables to someone else?

+ What are variables good for?

UNIT 4 ACTIVITY
EXTENSIONS OBJECTIVES
By completing this activity, students will:
+ become more familiar with the concepts of
conditionals, operators, and data by exploring
SUGGESTED TIME
30–45 MINUTES programs that illustrate common game mechanics

ACTIVITY DESCRIPTION RESOURCES

❑ Optionally, show example projects from the Extensions ❑ Extensions handout

studio and have the Extensions handout available to ❑ Extensions studio
guide students. http://scratch.mit.edu/studios/475619
❑ Give students time to explore the code of programs in
the Extensions studio to investigate different ways REFLECTION PROMPTS
games can be increased in difficulty or extended. Ask
students to select one or more extensions to add to
+ What are different ways of increasing difficulty in a
their previously started maze, pong, or scrolling game
game?
projects. Give students time to experiment and
+ Which extensions did you add to your game project?
incorporate the extension(s) into their games.
+ Describe your process for including the extension(s)
❑ Allow students to share their extended game projects in your game?
with one another. We suggest facilitating the
pair-share or design demo activity to let students REVIEWING STUDENT WORK
share their games and demonstrate what they learned.
❑ Ask students to think back on the design process by + Were students able to incorporate extensions into
responding to the reflection prompts in their design their original game projects?
journals or in a group discussion.

NOTES NOTES TO SELF

+ To provide more scaffolding for students needing extra ❑ _______________________

support, we suggest walking through one extension
sample program (e.g., levels) as a class and helping ❑ _______________________
students add the extension to their game projects.
+ The backpack tool is one way students can incorporate ❑ _______________________
parts of the extension projects into their starter ❑ _______________________
games. Learn more about backpack at
http://bit.ly/scratchbackpack
 EXTENSIONS
+ SCORE http://scratch.mit.edu/projects/1940443
Demonstrates how to set and change a score. Receive 10 points
every time the Scratch cat is clicked.

+ LEVELS http://scratch.mit.edu/projects/1940453
HOW CAN YOU EXTEND AND Demonstrates how to change levels. Score increases by 1 every time
REIMAGINE GAMES IN SCRATCH? the space bar is pressed. Level increases by 1 for every 10 points.

Get into game design by adding extended + TIMER http://scratch.mit.edu/projects/1940445

features within your Scratch project! Demonstrates how to use a timer. Use the mouse to navigate the
Choose at least one (or more!) of the Scratch cat to Gobo.
following extensions and add it to your
previously started maze, pong, or + ENEMIES http://scratch.mit.edu/projects/1940450
scrolling games. Demonstrates how to add an enemy. Avoid the tennis ball by using
the up and down arrow keys.

+ REWARDS http://scratch.mit.edu/projects/1940456
START HERE Demonstrates how to collect items. Use the arrow keys to move
the Scratch cat around to collect quest items.
❑ Go to the Extensions studio:
http://scratch.mit.edu/studios/475619 + MOUSE http://scratch.mit.edu/projects/25192659
Demonstrates how to program the mouse to control game play.
❑ Choose one (or more) of the extensions to Move the mouse to move the paddle.
explore.
❑ Incorporate your choice into your previously + RESTART http://scratch.mit.edu/projects/25192935
Demonstrates how to make a button to restart the game. Click on
started game projects!
the RESTART button to restart.

+ MENU http://scratch.mit.edu/projects/25192991
Demonstrates how to display a menu screen at the beginning of
the game. Click START or DIRECTIONS on the menu screen.

+ MULTIPLAYER http://scratch.mit.edu/projects/25192711
Demonstrates how to add another player to the game. Player 1
uses the arrow keys to navigate Pico through the maze, and player
2 uses the W, A, S, D keys to navigate Nano through the maze.

THINGS TO TRY FINISHED?

+ The backpack can be an extremely useful tool while + Add another extension to your maze, pong, or scrolling
programming in Scratch. It can store everything from game.
lines of code, to music files, to sprites, and more. Try using + Challenge yourself to do more! Continue going through
it to incorporate extensions into your game projects. each of the extensions and add them to your games.
+ Alternatively, sketching out ideas and bits of code in your + Help a neighbor!
design journal is another great method for planning how + Share your project with a neighbor and give each other
to incorporate your extensions. feedback on your games.
 UNIT 4 REFLECTION
EXTENSIONS
NAME:

REFLECTIONS RESPOND TO THE FOLLOWING REFLECTION PROMPTS

USING THE SPACE PROVIDED BELOW OR IN YOUR
DESIGN JOURNAL.

+ What are different ways of increasing difficulty in a game?

+ Which extensions did you add to your game project?

+ Describe your process for including the extension(s) in your game?

UNIT 4 ACTIVITY
INTERACTIONS OBJECTIVES
By completing this activity, students will:
+ explore different approaches to making projects
interactive by solving a series of nine
programming puzzles
+ gain more fluency in the concepts of conditionals,
operators, and data, and the practice of testing and
debugging

ACTIVITY DESCRIPTION RESOURCES

❑ On their own or in small groups of 2-3 people, ❑ Interactions handout

challenge students to further explore Scratch by ❑ Interactions studio
creating Scratch programs that solve each of the nine http://scratch.mit.edu/studios/487213
Interactions programming puzzles. These Interactions
puzzles explore Sensing blocks, engaging some of the
more advanced concepts in Scratch related to
REFLECTION PROMPTS
interactivity. Optionally, have the Interactions handout
available to guide students during the activity. + Which puzzles did you work on?
+ What was your strategy for solving the puzzles?
❑ Each puzzle can have several possible solutions. Invite
+ Which puzzles helped you think about your game
students or groups to share different solutions and
project?
strategies. We suggest the Pair-Share or Design Demo
activity to allow students to share their work and
describe their process. Optionally, have students add REVIEWING STUDENT WORK
their projects to the Interactions studio or a class
studio.
+ Are the puzzles solved?
❑ Ask students to think back on the challenge by + Did students explore other approaches for solving
responding to the reflection prompts in their design the puzzles?
journals or in a group discussion. + Are there certain blocks or concepts students are
still struggling with? How might you help?

NOTES NOTES TO SELF

+ Choose particular challenges that highlight new blocks ❑ _______________________

or concepts that you would like students to explore. Or
let students invent their own interaction puzzle ❑ _______________________
prompts.
+ Repurpose these puzzles as an unstructured activity for ❑ _______________________
students who finish other activities early or as a ❑ _______________________
warm-up challenge. Create a puzzle jar: print out, cut,
fold, and place copies of each puzzle description in a
jar. Then, let students pick puzzles from the jar to
solve.
 INTERACTIONS ❑ PUZZLE 1: Whenever you press the B key, the sprite gets a little
bigger. Whenever you press the S key, the sprite gets a little smaller.

WHAT DIFFERENTIATES A SCRATCH ❑ PUZZLE 2: Whenever the sprite hears a loud sound, it changes color.
PROJECT FROM A STILL IMAGE OR A VIDEO?

Tackle these nine puzzles that engage some of ❑ PUZZLE 3: Whenever the sprite is in the top 25% of the screen, it
the more advanced concepts in Scratch related to says "I like it up here."
interactivity. Each of these challenges has several
possible solutions.
❑ PUZZLE 4: When the sprite touches something blue, it plays a high
note. When it touches something red, it plays a low note.

START HERE ❑ PUZZLE 5: Whenever two sprites collide, one of them says: "Excuse
me.”
❑ Create a Scratch program for each of the nine
interactivity puzzles.
❑ PUZZLE 6: Whenever the cat sprite gets near the dog sprite, the dog
turns and runs from the cat.

❑ PUZZLE 7: Whenever you click on the background, a flower appears

at that spot.

❑ PUZZLE 8: Whenever you click on a sprite, all other sprites do a

dance.

E L I N G
FE
❑ PUZZLE 9: Whenever you move the mouse-pointer, the sprite follows
but doesn't touch the mouse-pointer.

U C K ?
ST E THIN
GS…
HES
O KAY ! TRY T FINISHED?
THAT’S

❑ Before getting started in Scratch, write down ideas in + Add each of the projects you create to the Interaction
your design journal for possible ways of programming Studio: http://scratch.mit.edu/studios/487213
each of the interactivity puzzles. + Help a neighbor!
❑ Work with a neighbor. Collaborating with a partner can + Discuss your strategies for approaching each puzzle with
be a great way to solve problems and gain new a partner. Take notes about the similarities and
perspectives on ways of programming in Scratch! differences in your methods.
 UNIT 4 REFLECTION
NAME:
INTERACTIONS
REFLECTIONS RESPOND TO THE FOLLOWING REFLECTION PROMPTS
USING THE SPACE PROVIDED BELOW OR IN YOUR
DESIGN JOURNAL.

+ Which puzzles did you work on?

+ What was your strategy for solving the puzzles?

+ Which puzzles helped you think about your game project?

UNIT 4 ACTIVITY
DEBUG IT! OBJECTIVES
By completing this activity, students will:
+ investigate the problem and find a solution to five
debugging challenges
SUGGESTED TIME + explore a range of concepts (conditionals,
15–30 MINUTES operators, and data) through the practices of
testing and debugging

ACTIVITY DESCRIPTION RESOURCES

❑ Optionally, have the Unit 4 Debug It! handout ❑ Unit 4 Debug It! handout
available to guide students during the activity. ❑ Unit 4 Debug It! studio
http://scratch.mit.edu/studios/475634
❑ Help students open the Debug It! programs from the
Unit 4 Debug It! studio or by following the project
links listed on the Unit 4 Debug It! handout. Encourage REFLECTION PROMPTS
students to click on the “Look Inside” button to
investigate the buggy program, tinker with problematic
+ What was the problem?
code, and test possible solutions.
+ How did you identify the problem?
❑ Give students time to test and debug each Debug It! + How did you fix the problem?
challenge. Optionally, have students use the remix + Did others have alternative approaches to fixing the
function in Scratch to fix the bugs and save corrected problem?
programs.
❑ Ask students to reflect back on their testing and REVIEWING STUDENT WORK
debugging experiences by responding to the reflection
prompts in their design journals or in a group + Were students able to solve all five bugs? If not, how
discussion. might you clarify the concepts expressed in the
❑ Create a class list of debugging strategies by collecting unsolved programs?
students’ problem finding and problem solving + What different testing and debugging strategies did
approaches. students employ?

NOTES NOTES TO SELF

+ This activity provides an opportunity to check in with ❑ _______________________

students who might need some additional attention or
support, particularly around the concepts of ❑ _______________________
conditionals (e.g., if), operators (e.g., arithmetic,
logical), and data (e.g., variables, lists). ❑ _______________________
❑ _______________________
 DEBUG IT! ❑ DEBUG IT! 4.1 http://scratch.mit.edu/projects/24271192
In this project, the "Inventory" list should be updated every time
Scratch Cat picks up a new item. But Scratch Cat can only pick up
the laptop. How do we fix the program?
HELP! CAN YOU DEBUG THESE FIVE SCRATCH
PROGRAMS?

In this activity, you will investigate what is going

❑ DEBUG IT! 4.2 http://scratch.mit.edu/projects/24271303
awry and find a solution for each of the five
Debug It! challenges. In this project, Scratch Cat gets 10 points for collecting Yellow
Gobos and loses 10 points for colliding with Pink Gobos. But
something isn't working. How do we fix the program?

START HERE ❑ DEBUG IT! 4.3 http://scratch.mit.edu/projects/24271446

❑ Go to the Unit 4 Debug It! Studio: In this project, Scratch Cat is thinking of a number between 1 and
http://scratch.mit.edu/studios/475634/ 10. But something is wrong with the guess checking -- it doesn't
work consistently. How do we fix the program?
❑ Test and debug each of the five debugging
challenges in the studio.
❑ Write down your solution or remix the buggy
program with your solution. ❑ DEBUG IT! 4.4 http://scratch.mit.edu/projects/24271475
In this project, the "# of hits" display should increase by 1 every
time the Scratch Cat is hit by a tennis ball. But the "# of hits"
increases by more than 1 when Scratch Cat is hit. How do we fix
the program?

❑ DEBUG IT! 4.5 http://scratch.mit.edu/projects/24271560

EE L IN G
F
In this project, Scratch Cat is navigating a maze to get to the
yellow rectangle. But Scratch Cat can walk through walls. How do

U C K ? we fix the program?

ST E THIN
GS…
Y THES
THAT’S
OKAY ! T R
FINISHED?

❑ Make a list of possible bugs in the program. + Add code commentary by right clicking on blocks in your
❑ Keep track of your work! This can be a useful reminder of scripts. This can help others understand different parts of
what you have already tried and point you toward what to your program!
try next. + Discuss your testing and debugging practices with a partner.
❑ Share and compare your problem finding and problem Make note of the similarities and differences in your
solving approaches with a neighbor until you find strategies.
something that works for you! + Help a neighbor!
 UNIT 4 REFLECTION
NAME:

DEBUG IT!
REFLECTIONS RESPOND TO THE FOLLOWING REFLECTION PROMPTS
USING THE SPACE PROVIDED BELOW OR IN YOUR
DESIGN JOURNAL.

+ What was the problem?

+ How did you identify the problem?

+ How did you fix the problem?

+ Did others have alternative approaches to fixing the problem?