Warm Up (10 min)

Introduction

Help the class understand that functions are simply a chunk of code that has a name. Once defined, you can use that name over and over in your program to tell the computer to run the chunk of code that you assigned to it.

Bridging Activity - Functions (15 min)

This activity will help bring the unplugged concepts from "Functions Unplugged: Songwriting" into the online world that the students are moving into. Choose one of the following to do with your class:

Unplugged Activity Using Some Blockly

Pick a song to play that the students enjoy and print out the lyrics. You can use the same song from "Functions Unplugged: Songwriting." Break your class into groups or pairs. Pass out the printed out lyrics (including the repeated chorus) and the basic function blocks from Unplugged Blocks (Courses C-F) - Manipulatives to each group or pair of students. See lesson tip for details.

Ask the students to cross out any part of the song that can be made into a function (the chorus is a good example) and put it into the function blocks provided. Students should fill in the function declaration with a function name and the words of the repeated lyrics. Once the function declaration is done, ask the students to fill in the function calls and place them on top of the crossed out lyrics.

Once every group or pair is done, ask the class where they put their functions and why. Did everyone make the same function? How often is the function repeated?

Preview of Online Puzzles

Pull up a puzzle from the lesson. We recommend puzzle 9. As a class, work through the puzzle without using functions. Once you have gotten the solution, display it on a white board or overhead. Ask the class to point to the repeated code. Ask the class how they would simplify the program. Why can you not just use a loop?

On the white board or overhead, rewrite the program without the repeated code, but leaving one line space. In that/those line space(s), call a function. Off to the side, declare the function like the left example block in the lesson tip. Ask the class what they think the code will do now.

Open up a discussion with the class on why functions could be useful in programming. Invite students to discuss the difference between functions and loops.

Main Activity (30 min)

Online Puzzles

We recommend providing paper and pencils for students to write (or draw) out ideas. Also, if students are having trouble recognizing patterns, have them work with a partner on the harder puzzles.

Wrap Up (15 min)

Journaling

Having students write about what they learned, why it’s useful, and how they feel about it can help solidify any knowledge they obtained today and build a review sheet for them to look to in the future.

• What was today's lesson about?
• How do you feel about today's lesson?
• What did your functions do in the programs you wrote today? How did that help you?
• When should you use a function instead of a loop?