Functions in Unit 4 (5 minutes)

💷 This lesson builds on what students have seen in Unit 4. Remind participants of how functions are introduced in Unit 4 using the slides.

• We look at functions as a way to organize code and reduce the number of lines of code we need.
• Students look at the “updateScreen” function for several apps to see how the code inside the function definition works

Lesson demo (15 minutes)

💷 Run through the slides from the Explore lesson. This is not intended to be a model lesson, but instead a demonstration on how the content will run.

Slides	Speaker Notes
	Say: This lesson starts off with the function “makeCake” which creates a cake with a number of tiers and a flavor. Click for animation
	Say: If I flip over the envelope, and open it up there's a recipe inside. This recipe is going to tell me how to make the cake I've specified.
	Say: To do this, I'm going to replace tiers with 3 and flavor with lemon, every time those words show up in the recipe. But notice - this recipe is pretty general. I could use it to make lots of different types and sizes of cake. Click for animation
	Say: Ok, let's make our cake. Remember, each time I come across tiers or flavor, I'm going to replace that word with the appropriate value. Once I'm done, I will have baked a 3 layer lemon cake! Click for animation: There are several steps to click through here. Take it slow so participants can see each part.
	Say: This is a function! It should look familiar, but it has a few extra parts. This function has parameters. Parameters are used as plaeholders for values that will be passed through the function. Click for animation Say: Those values passed to the parameter are called arguments. Click for animation
	Say: Having a function with parameters allows our function to be used for a greater variety of purposes. Imagine if I created a function for makeLemonCake,makeChocolateCake, and makeVanillaCake… it could go on for awhile! By creating a function with parameters, I can create different outputs more easily by giving it different values or arguments. This summarizes the need for functions with parameters. In the lesson plan, this is also when students are given an activity guide that asks them to create a function that describes how to make a house with given parameters. Students use the manipulatives to create the function and write the directions inside the function in pseudocode.
	Say: The second half of the lesson is dedicated to understanding how “return” works. To do this, we look at a function “cakeCost”. It has tiers and flavor also as parameters. Click for animation
	Say: Let's open the envelope and check out how this function works.
	Say: There are a few new things here. First, we've created two local variables. Remember, the local variables are contained within the function and can't be updated or accessed outside of the function. We learned about this when we discussed variable scope. Click for animation In this function, a decision (in this case, how much to charge per flavor) is made based on the argument passed through the parameter. Click for animation Finally, the total is returned, but returned where? What does that mean? Click for animation
	Say: If the program hits a return at any point in running a function, it will stop and a value will be "returned". Where is it returned? To the place in the program where the function was called.
	Say: Here's how this looks in JavaScript. It's ok if it's a little confusing. You'll get to play with this in Code Studio in the next lesson. For now, notice how the statement is set up. A variable is set up with the name cakeCalculator. This gets the value that is returned from the function cakeCost which has two arguments 3 and lemon passed through the parameters. After the function is evaluated, cakeCalculator now stores the value 12.
	Say: We can also print to the console like so. **Do This: Read through as a class.
	After we walk through this as a class, students complete a second challenge in the activity guide to create a function that returns the cost of building a house.

Reflection (10 minutes)

(2 minutes) 💷 Quick Lesson Summary

This is time to zoom out and take a big-picture look at the lesson and its key beats. This includes:

• Warm-up: Asking students, Why would you want to make your code easier to work with or read?
• Activity
  • Students use stickies, envelopes and paper to follow along as the teacher walks through the makeCake function.
  • Students are introduced to the vocabulary of parameters and arguments
  • Students write their own function in pseudocode for a “build a house” function and trade functions with other students to follow their directions with specific arguments.
  • Students return to the full class and learn about what a return does in a function through the cakeCost function
  • Students create their own function that returns the cost of a house
• In the wrap-up the teacher summarizes everything they learned in the lesson.

(7 minutes) Reflection and Discussion

(2 minutes) 💷 Journaling prompt: Now that you have an idea of how this lesson runs, think back to what we thought of an inclusive classroom looking and sounding like.

• Which of those things could you expect to see in this lesson?
• What are some concrete strategies that you might enact to fight barriers to inclusion in this lesson?

(5 minutes) Full Group Share Out and Discussion

• 💷 Make sure to capture the ideas presented here in the slides.
• This should also be an actively facilitated conversation. This means, as a facilitator, you should be asking probing questions that support the discussion goal.

(1 minute) Wrap Up