Prompt: Imagine you needed to write a 5-step set of instructions for going through your morning. What would they be? Write down your steps and be ready to share.

Discussion Goal

Goal: This conversations demonstrates to students that they often use a high level name or description for much more complex behavior. It is motivating the value of grouping or combining lots of smaller steps under a larger name and provides some of the justifications for creating functions within programs. Namely, high level steps make it easier to understand and reason about a process.

Content Corner

Breaking Down Processes: The order in which they are breaking down a larger task here also mirrors how they'll be asked to write code with functions. Often programmers first write the name of the function they intend to write based on what it should do before actually going in and writing the details.

Discuss: Student should write 5-step instructions for their morning and share with a neighbor. Ask a couple of students to share with the class.

Prompt: This set of instructions is pretty easy to follow and understand. They're at the level you might think about when describing your day to a friend. Now let's go a level deeper. Pick one of your 5 steps and split it into 5 smaller steps you need to complete that larger task. Be ready to share your ideas again.

Discuss: Students should share their smaller steps. Again ask some volunteers to subsequently share their original step and how they split it up.

Discuss: This is getting interesting. It seems like the first time we gave our steps we were "hiding" some of the details necessary to complete the task. Let's try this once more. Take one of your 5 smaller steps and split it up again into 5 even smaller steps.

Discuss: Ask students to share their steps one more time. Again ask some volunteers to share how they broke up one of their steps into even smaller steps.

Prompt: Imagine we had split every one of your first 5 steps into 5, and then split all of those steps again. This would mean we would have a high level set of instructions, and at the bottom a really low-level or detailed set of instructions. Be ready to respond to the following questions.

Discuss: Ask students to share their thoughts and opinions. After a couple of minutes move the conversational to the transitional comment below.

Remarks

Sometimes details are important, but often high level steps are much easier to reason about and make it clear what's happening. In programs the same thing is true. We've learned that blocks like velocityX or isTouching actually just contain code that we could've written ourselves. Using these commands, or abstractions, is really helpful since we can think about code at a high level. Today we're going to learn how to group lots of commands to create a single new block our own. In programming when we create a new block like this we call it a function.

Transition: Move students into Code Studio where they will learn to create an call functions.

Discussion Goal

Goal: Use this first prompt to review what students learned today. When they create a function they are creating their own block that they can call or use whenever they like. They saw at least two primary motivations for creating functions today including.

Prompt: Why would we say that functions allow us to "create our own blocks?" Why is this something we'd want to do?

Discuss: Have students discuss at their table before talking as a class.

Discussion Goal

Goal: Students should review the definition of abstraction as "a simple way of representing something complex". Note that a function is an abstraction because it allows you to create one simple name for a more complex block of code.

Prompt: Write down your own definition of an abstraction? Why would a function count as an abstraction?

Discuss: Have students discuss at their table before talking as a class.

Remarks

Functions are a useful tool for helping us write and organize more complex pieces of code. As we start looking to end of the unit and your final project, being able to keep your code organized will be an important skills.