Target age range: 8 – 11 years

Duration of lesson: approxmately 1 hour

Size of class: approximately 15 students

Kids should have a basic understanding of how to

work with computers and how to do the simple

functions on Scratch that were covered in Lesson

Plan 1 (changing the appearance of the stage and

sprite, creating more than one sprite, giving simple

commands to sprites).

Setup

Skills Required

Objectives• Students should review the concepts they

learned on Day 1 to make sure that they retained the information.

• They should become engaged in the material that they are to learn in this lesson.

• Students should be able to use:• Other control functions:

• Forever• If/Else• Repeat• Broadcast

• Sensing

If/Else: http://scratch.mit.edu/projects/dill1233/1214042

Sensing: http://scratch.mit.edu/projects/dill1233/1214042

Materials

Resources for this Lesson

• A computer for each student (with Scratch installed) OR for every two students

• Speakers/headphones so that students can hear sounds

• A projector and accompanying screen

Review and Engaging theStudents

We strongly recommend going over all of the things learned on day 1 to make sure the kids remember and have absorbed the information.

If you have completely new students, one option is peer programming: partner a new student with a student who attended the previous lesson. The idea is that the more experienced student will better understand Scratch since they have to explain what they already know to a newbie.

To engage the students, you can show them the If/Else and Sensing programs, found in “Resources for This Lesson.”

In order to teach kids more about changing the position of the sprite, it is important that they have a basic understanding of the coordinate

system and how to work with x- and y-coordinates. Scratch comes with a Cartesioncoordinate background. Go to “Import” under

the Stage tab.

Make sure they know that the purpose of the coordinate plane is to know the position of objects using the

horizontal and vertical lines (“axis”).

First, it is important to relay that “y” denotes the vertical position and “x” denotes the horizontal position. They

are always told in the format,

(x, y)Go through the meaning of positive and negative x and y coordinates. Go through a few examples to make sure

they understand the basic theory of it.

This may take anywhere from 5 – 20 minutes depending on the knowledge level of the kids. They may loose

interest, but it is important that they at least know the meaning of “set x,y to 0” for later on.

As the name suggests, the Forever block makes a script go on “forever” until you stop

it.

To the right is a good starting to script to get accustomed to what the

block does.

The “forever” block is very important; it is critical to understand in order to develop more complicated

programs. The more you use it, the more you understand about it. Let the kids do a simple script with forever to

understand the basics of what it does.

If/else and repeat are essential for more complicated programs.

◦If/else follows basic principles: If “this” happens, then do one action. Else, if “this” does not happen, then do another action.

◦Repeat just repeats the segment of script that is inside of it the number of times specified.

Here is an example of a program that

uses If/Else and Repeat. We use the two

dragons found in the “fantasy” folder of

importable sprites. Set the rotation of

the dragon to left and right.

Two scripts need to be made. The first

script allows the dragon to bob up and

down smoothly, and the second checks

whether or not the space key is pressed

(which utilizies a block from Sensing)

to let the dragon breath fire.

The broadcast command can be used to interact between Sprites or

different scripts. When something in a script occurs, you can tell it

to “Broadcast” something. Then, you can create another script that

“receives” the broadcast and subsequently performs an action.

Name the

broadcast

anything you

would like.Then, create another control block as a separate

script: “When I receieve...” and choose the

broacast you created. Attach an action to when

you receive the broadcast.

As you can see from the Pen drop-down

menu, there are many different ways to

manipulate Pen. We will now go over

them.

Pen down You must put “pen down” in a

script for pen to appear as the sprite

moves. Here is a simple script that

enables you to see this.

Pen up You must put “pen up” in a script to

stop the pen from being drawn as a sprite

moves. The script the right shows what this

block can do.

Clearing pen It is important to know how to

clear the pen off of the stage, too; it does not

go away when you stop the script. In order to

completely take away all of the pen that has

been put on the stage, there is a handy “clear”

command, available in the “Pen” blocks.

Let the kids play with the “pen

down”, “pen up”, and “clear”

commands.

Pen color You can change the pen color in

multiple ways with pen. There is a group of three

blocks in the Pen menu that control this.

The First and Third blocks are ways that you

can set the pen to a specific color.

The Second block allows you to change the

color of the pen. It can be combined with

“forever” or “repeat” to continuously change

the color instead of “setting” it to different

colors repeatedly.

Pen shade As the name indicates, including

these blocks in a script will set/change the

shade of the pen color.

Pen size These blocks change/set the size of

the pen to your liking.

Stamp This is a Pen function in that as the

sprite moves, this block creates “stamps” of

itself along the path of the sprite.

As a basic introduction to some of the functions of Operators, you

can input scripts similar to the following. Nothing happens to the

Sprites, but Scratch does respond with something back to you.

You can also put operators into other operators and other blocks.

Here are some examples that the kids can incorporate into their

programs.

The sensing blocks allow sprites to interact with their world. We have encountered a few of the blocks

before.

In this lesson, three sprites are used:

Gobo (found in fantasy), Mr. Sun

(found in fantasy), and RedBox which

is made from scratch using the box

tool in Paint Editor.

The main blocks that we will be using are

touching sprite and touching color and the

“When Sprite Clicked” starting event from the

control category.

The script to the right belongs to the

Gobo sprite. It specifies that if the

Gobo sprite is touching the sprite Mr.

Sun, then it will say “Good Day, Mr.

Sun!” It will also broadcast “HelloSun”.

If it is touching the red box, it will say

“Hmm... It looks like a red box.”

The last script belongs to the “Mr. Sun”

sprite and replies to the “Gobo” sprite.