Transcript tenSessionScratchL5.ppt

Scratch Programming
Session 5 of 10
Review + Multiple Sprites
Objectives for Session 5
• Review Binary
• Review Algorithms
• Multiple sprites
Binary
• What is Binary?
• What Numbers are used in Binary?
Binary conversion Algorithm
0
r
1
• Convert 25 into binary
1
r
1
– 1/2 =
3
r
0
– 3/2 =
6
r
0
– 6/2 =
12
r
– 12/2 =
– 25/2 =
• 25 in Binary is 11001
1
Try these examples on your own:
• Convert to Binary:
36
52
67
1342
• Bonus: convert this from binary to decimal
110011
The other way around
• How do you convert 11001 into Base 10 (our
number system)?
16
8
4
2
1
1
1
0
0
1
• 16+8+0+0+1 = 33
Try these numbers
• 010101
• 011111
• 000011
32
16
8
4
2
1
Game
The number must be:
Less than 7 digits in binary or
Less than 100 in Base 10
• 2 Teams (Left Side vs. Right Side)
• Each team comes up with a number, in binary
or in base 10
• The other team has to convert it.
• 30 seconds to answer
• Highest Score after 5 rounds wins!
ASCII
• ASCII stands for the American Standard Code
for Information Interchange
• It’s a way for computers to represent letters or
characters in Binary
• Each letter or symbol gets a specific sequence
of numbers
ASCII
• Example
– The character “A” is represented in binary as
01000001
– The character “a” is represented as 01100001
• All the characters are represented in some
form of this binary code
Activity
• Close Scratch
•Dr. Stockman’s Block
Coding Activity
Algorithms
• What are Algorithms again?
– Instructions or Recipes for how to do a specific thing, such
as find the area of a square
• What Algorithms have we done before?
– Area of a Square, Perimeter, Area of a triangle, Average
number of people
• What other Algorithms can you think of?
Variable Practice
• Let’s calculate the distance between 2 points
• First, we ask the user for point 1
– Ask “What is point 1” and wait
• Then we save that as a variable
– Set point1 to answer
• Now do the same for Point 2
Variable Practice Cont.
• Now we need to find the distance between
the 2 points
– Set Result to Point2 – Point1
– Say Result
Exercise: Calculate Average Age
• Calculate the Average of two ages
• Hints:
– 3 Variables (Age1, Age2, Result)
– Ask for Age1 and Age2
– Average of 2 ages is (Age1+Age2)/2
– Say the Result
• Show us when you’re done
BONUS:
Can you make it
average more
than 2 people?
Multiple Sprites
• So far, we’ve only been using a single sprite to
do everything.
• Scratch is designed to handle more than one
Sprite
Adding A new sprite
• On the bottom left
panel of scratch, click
“import sprite”
• Choose the sprite
you want to import
• Click “okay”
Important things to know
• Notice that the scripts from your first sprite
are NOT visible when you have this sprite
selected
• Any scripts you add to this sprite will only
work with THIS SPRITE.
Naming your sprites
• Something helpful when you have multiple
sprites is Naming them something you’ll
recognize later.
• Lets do this now:
Changing a Sprite’s name
• Click on the sprite whose name
you want to change
• Click in the Box near the sprite’s
picture
• Type in the new name and hit
enter
Review
• You now know:
– How to convert a number to and from binary
– How computers recognize numbers and letters
– How to make an algorithm in Scratch
– How to add additional sprites to your Scratch
Program