scratch lesson 1 - coderdojo nelson€¦ · the scratch stage • the scratch stage is 480 pixels...
TRANSCRIPT
![Page 1: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/1.jpg)
Scratch Primary Lesson 5
The XY Coordinate System
creativecomputerlab.com
![Page 2: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/2.jpg)
The Scratch Stage• The scratch stage is 480 pixels wide and 360
pixels high:
480
360
creativecomputerlab.com
![Page 3: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/3.jpg)
The Pixel• The pixel is the smallest single component of a digital
image or a computer screen.• Pixels form a grid across the screen. Each pixel can be
given a color which makes up its part of an image.• In Scratch, one unit of x or y, or one step is equal to one
pixel:
creativecomputerlab.com
Zoom in on the cat to see theindividual pixels in the image
![Page 4: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/4.jpg)
X: -100
X Number Line• These are the x values for the scratch stage
– Where is 0? --Why are some x values negative?– What is half of 480?
Values for X:X: 100
480
creativecomputerlab.com
![Page 5: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/5.jpg)
Try This Experiment:• Build the script shown below:• Check the box to display the x position:
• Run the script and watch the sprite’s x values change:
• What is the x position when the script ends?creativecomputerlab.com
![Page 6: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/6.jpg)
X Number Line• The left half of the stage has negative (-X) values.• The right half of the stage has positive (X) values
Negative X-X
X < 0-100 100
Positive XX
X > 0
creativecomputerlab.com
480
![Page 7: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/7.jpg)
Move With The Arrow Keys• A negative number moves in the opposite
direction as a positive number.
• Positive numbers move x to the right ->
• Negative numbers move x to the left <-
creativecomputerlab.com
![Page 8: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/8.jpg)
Y Number Line• These are the y values for the scratch stage
– Where is 0? --Why are some y values negative?– What is half of 360?
Y: -100
Y: 100
Negative Y-Y
Y < 0
Positive YY
Y > 0
creativecomputerlab.com
360Values for Y:
![Page 9: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/9.jpg)
X and Y Values Combined
x, y-x, y
-x, -y x, -y
There are 4 ‘quadrants’. Each quadrant has a different combination of positive or negative x and y values:
creativecomputerlab.com
![Page 10: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/10.jpg)
The XY Coordinate System• Start a new project.• Select the “x-y grid
backdrop for the stage:
creativecomputerlab.com
![Page 11: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/11.jpg)
Moving In the XY Coordinate System
• Hook the right arrow key up to “change x by 10”:
creativecomputerlab.com
• How are we going to move left?
• What about moving up and down?
• Can you make the sprite move with all 4 of the arrow keys by changing x and y?
![Page 12: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/12.jpg)
Fun With The• Starts drawing
• Stops drawing
• Erases all drawings
• Sets the pen thickness
• Sets the pen’s colorcreativecomputerlab.com
![Page 13: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/13.jpg)
Make A Drawing Program
– Hook all four arrow keys to change x and y by 10
– Now double click on the ‘pen down’ block:
– Set the pen thickness:
– Set the pen color:
creativecomputerlab.com
Now move around with the arrow keys and draw!If you screen gets too messy you can click on
![Page 14: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/14.jpg)
Make Rainbow Tracks• Program the scripts to
change the pen color each time the sprite moves. See what happens.
creativecomputerlab.com
![Page 15: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/15.jpg)
Going Places• Lets make the cat go to different XY locations on
the stage.• Make the cat go to the center of the stage:
• Make the cat go to the lower left of the stage:
• Make the cat glide to the upper right of the stage:
• See what happens when you make the glide for more than one second.
creativecomputerlab.com
![Page 16: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/16.jpg)
Explore the X and Y Space• Go to the “xyPosition” project at :
http://scratch.mit.edu/projects/12776565/• You can search for it by typing in “creativecomputerlab”,
then click on the “xyPosition” project:
• Play with the project and see the values for x and y change.creativecomputerlab.com
![Page 17: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/17.jpg)
The Ant Farm GameThis is a programming challenge. Program the ant to reach the food without touching the sides in 2 ways:
1. Move the ant by using the arrow keys.
2. You are NOT allowed touse the arrow keys. You have to write a script so that the ant will move by itself whenyou push the 'Go!' button.
creativecomputerlab.com
![Page 18: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/18.jpg)
Make Your Own Copy Of The Ant Farm Game
http://scratch.mit.edu/projects/12778304/•Make your own copy of the game by:
1. Clicking on 2. When you are in the project click on 3. Change the name of the project from
to include your name:
creativecomputerlab.com
• Go to the “Ant Farm” project at
![Page 19: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/19.jpg)
Inside The Ant Farm Game
creativecomputerlab.com
• The Ant: Make the ant move by adding scripts to move with the arrow keys:
Be careful that the ant doesn’t touch thesides of the tunnel! See what the script doesand play with it.
Challenge 1: Use arrow keys to move
![Page 20: Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels wide and 360 pixels high: 480. 360. creativecomputerlab.com. The Pixel • The pixel](https://reader033.vdocument.in/reader033/viewer/2022052720/5f0830ae7e708231d420c95a/html5/thumbnails/20.jpg)
Inside The Ant Farm Game
creativecomputerlab.com
• The Ant: Make a script which makes the ant• move through the tunnel by itself without
using the arrow keys.
Hint: You can use these blocks:
You win when the ant touches the food at the upper right.
Challenge 2: Move the ant using a script.