IntroducingScratch the Cat

Shapes and Colors

Computer Programs

• Tell the computer what to do

• Without Programs – Computers do nothing

• Computer Programmers write the programs that make our computers do stuff

Scratch

• Scratch is a way to write computer programs–We can tell Scratch what to do

–We have to be very specific

–We have to be very exact

–We have to be very complete

Open Scratch

• Lets look at a program that tells Scratch to draw shapes

• Double-Click on the File Named: SHAPES.SB

You Should See This:

Draw a Square

• Lets See Scratch Draw A Square• Click on the Green Flag

Draw a Square

• Hit the “S” key • Watch Scratch Draw a Square

Draw a Square

• How did we get Scratch to Draw a Square???

• How do you draw a Square?

• We need to “tell” Scratch the same thing in our computer program

Program

• Look at the Middle Block in Scratch• Code - Instructions

Drawing a Square- Instructions

Key to Press

Drawing a Square- Instructions

Color

Drawing A Square - Instructions

Sides

Drawing A Square - Instructions

Size

Drawing A Square - Instructions

How to Turn

Change Square - Color

See the Color – Click on this Box

Change Square - Color

Change the Color

Change Square - Color

Pick ANY Color

Draw a Square

• Hit the “S” key again• Watch Scratch Draw a Square in Your

Color

Need to Start Over

STOP

Need to Start Over

Start Over

Change Square - Size

See the Size – Click on this Box

Change Square - Size

Change the Size

Change Square - Size

Type A New Number

Draw a Square

• Hit the “S” key again• Watch Scratch Draw a Square with

the New Size

Drawing A Different Square - Sides

4 Sides in a Square

Drawing A Different Square - Sides

Change Number

Draw a Square

• Hit the “S” key again• Watch Scratch Draw a Square with

more or less sides

6 Sides

Drawing A Different Square – Sides – Put Back to 4

Put Back to 4

Drawing A Different Square – How to Turn

Amount to Turn

Drawing A Different Square – How to Turn

Change Number

Draw a Square

• Hit the “S” key again• Watch Scratch Draw a Square?

150

Drawing A Different Square – Turn – Put Back to 90

Put Back to 90

Program Does More

• Look at the Middle Block in Scratch• Code - Instructions

What Does this Do?

• Key Clicked?• Sides?

Draw The Shape

• Hit the “T” key • Watch Scratch Draw The Shape• Were you Right?

Make Some Changes?

ColorSize

Turns

Draw The Triangle Again

• Hit the “T” key • Watch Scratch Draw The Shape• See Your Changes?

Program Does More

• Look at the Middle Block in Scratch• Code - Instructions

What Does this Do?

• Key Clicked?• Sides?–Why is this

different–What is it doing?

Draw The Shape

• Hit the “R” key • Watch Scratch Draw The Shape• Were you Right?

Make Some Changes?

• Have to change in more than 1 place

ColorSize

Turns

Draw The Rectangle Again

• Hit the “R” key • Watch Scratch Draw The Shape• See Your Changes?

Program Does More

• Look at the Middle Block in Scratch• Code - Instructions

Lets Make Our Own

• Lets see what it takes to write our own program to tell the computer to draw a line:

• Click “FILE”

FILE

Lets Make Our Own

• Click on “NEW”

NEW

Lets Make Our Own

• Save Current Project:• Click “YES:

YES

New Program

Change Cat

• Lets use a different animal • Click

Delete Scratch

• Click Scratch

Pick a New Animal

• New – Click

Middle Star

Pick a New Animal

• New – Click “Animals” Folder

Animals

Pick a New Animal

• Click on any Animal• Can Scroll UP and DOWN

Animals

Scroll

Pick a New Animal

• Click: OK

OK

Pick a New Animal

• New Animal

Give Instructions

• Buttons Sort Instructions

Start

• Click ORANGE button: CONTROL

CONTROL

Flag (GO)

• Click on Flag

Flag

Flag (GO)

• Drag Flag to Middle

Flag

Flag (GO)

• Drag Flag to Middle

Drag to Middle

Start in Middle of Screen

• Click Blue Button: MOTION

Motion

Start in Middle of Screen

• Click on • Drag to Middle

Motion

Go To X:_ Y:_

Start in Middle of Screen

• Connect to Flag

Click to Flag

Start in Middle of Screen

• Change 10s to 0s

Change to 0

Start in Middle of Screen

• Change 10s to 0s

Change to 0

Line – Color / Width

• Click Green Button - PEN

Pen

Line – Clear

• Drag to Middle

CLEAR

Line – Color

• Connect To List

Connect to List

Line – Color

• Drag to Middle

Pen

Line – Color

• Connect To List

Connect to List

Line – Pick Color

• Click on the Box

Click BOX

Click BOX

Line – Pick Color

• Pick any Color

Click Color

Line – Size

• Drag to Middle

Set Pen Size

Line – Size

• Connect to List

Connect

Line – Size

• Change Size Change

Change to 15

Write Line

• Click• Drag to Middle• Connect to List

Pen Down

Put in List

Say Hello

• Make it Say Hello• Click on Dark Purple: LOOKS

LOOKS

Say Hello

• Click• Drag to Middle• Connect to List

Say HelloConnect

Test It

• Test – See if it works• Click

Green Flag

Test It

Test It

• No Line? Why?

Draw Line

• Click Blue: MOTION

Motion

Draw Line

• Click• Drag to Middle• Connect to List

Move 10 Steps

Connect to List

Draw Long Line

• Change Line from 10 to 150• Change to

• To 150

150

Test It

• Try It• Click

Code - Instructions

• What Can You Change?• How?