Scratch –Think Like a Computer 9-21-2015 Module 2 Lesson 1 Take out a piece of paper and head it with Your Name Scratch Mod 2 Lesson 1

Learning Objectives To understand how computers interpret instructions even if this means that the outcome is unexpected. To show that the person writing a computer program must have a very clear understanding of what needs to be done before writing the computer program. Once a computer program has been written it can be tested to make sure it functions as expected.

Would it be good if… People followed instructions exactly? “Go through that door” “All hands on Deck” “My way or the highway” “That will cost you an arm and a leg.”

Take out three pieces of paper Need three volunteers. Volunteers will go outside the class and develop instructions on how to draw the image given to them.

Draw the first Image No Talking allowed

Check the Image Hold up your drawings What were some of the problems you faced when trying to make the image?

Second Image Yes/No questions are allowed from the user (class) However, the programmer may not look at the drawings. The programmer may not ask questions

Check the Image Hold up your drawings What were some of the problems you faced when trying to make the image?

Third Image Yes/No questions are allowed from the Programmer. No questions allowed from the user (class).

Check the Image Hold up your drawings What were some of the problems you faced when trying to make the image?

Which drawing was easier to draw? Why? Was it helpful to be able to ask questions? Was it helpful to have the programmer able to ask questions? What would have been more helpful?

Summary Any unexpected outcomes? Do you see some things that can happen if a program is not clear? What about the importance of testing? Questions from the program to check the users progress.

Activity Using what you have learned today, write out the best instructions possible to create the last drawing. When completed, turn it into the Macintosh