AP CSP Day 11 - Introduction to Functions

Course Information

• Course: AP Computer Science Principles
• Unit: Big Idea 1 - Creative Development (CRD)
• Lesson: Day 11 (50 minutes)
• Learning Objective: CRD-1.K - Use functions appropriately

Learning Objectives

Primary Goals

Students will be able to:

1. Understand the concept of functions in programming
2. Create programs using user-defined functions
3. Test and refine function logic
4. Analyze real-world scenarios that require functions

AP Exam Alignment

• Big Idea 1: Creative Development (10-13% of AP Exam)
• Essential Knowledge: CRD-1.K.1, CRD-1.K.2, CRD-1.K.3
• Computational Thinking Practice: 1.A - Investigate the situation, context, or task

Lesson Structure (50 minutes)

Opening Hook (10 minutes)

1.1 Welcome & Lesson Preview (5 minutes)

Teacher Activities:

• Recap previous day's content on nested control structures
• Introduce today's topic on functions

Student Activities:

• Think about: "What are some examples where we use functions in daily life?"

1.2 Function Examples Challenge (5 minutes)

Activity: "Identify the Function"
Instructions:

• Groups of 4-6 students
• Identify functions in given scenarios
• Discuss the importance of functions

Purpose: Activate thinking about functions

Core Content Instruction (20 minutes)

2.1 What are Functions? (10 minutes)

Definition (CRD-1.K.1):

A function is a named block of code designed to perform a specific task.

Key Concepts:

• Function definition: def function_name(parameters):
• Function call: function_name(arguments)
• Return values: return result

Case Study: Using functions in a simple program

• Program: Calculate the area of a rectangle
• Function structure: def calculate_area(length, width): return length * width

2.2 Types of Functions (5 minutes)

Examples:

• Built-in functions: print(), len()
• User-defined functions: def custom_function():

Discussion Questions:

1. What makes a good function?
2. Can you think of an example where functions are used in daily life?
3. Why are functions important in programming?

2.3 Advanced Function Concepts (5 minutes)

Why is it important?:

• Reusability: Writing code once, using it multiple times
• Modularity: Breaking down problems into smaller parts

Discussion Questions:

1. How can we make functions reusable?
2. Why is modularity important in programming?

Hands-On Activity (15 minutes)

3.1 Group Project: Create a Program with Functions (15 minutes)

Activity: "Design a Program"
Instructions:

• Groups of 3-4 students
• Design a program that uses functions
• Test the program for correctness
• Present the program to the class

Materials:

• **Program design worksheet
• **Function usage checklist

Learning Goals:

• **Understand functions
• **Create programs using functions
• **Test function logic
• **Present ideas effectively

Assessment:

• **Group participation
• **Program quality
• **Testing thoroughness
• **Presentation clarity

Closure & Preview (5 minutes)

4.1 Key Concepts Review (2 minutes)

Today's Learning Highlights:

1. ✅ Understanding the concept of functions in programming
2. ✅ Creating programs using user-defined functions
3. ✅ Testing and refining function logic
4. ✅ Analyzing real-world scenarios that require functions

AP Exam Connection:

• These concepts will appear in AP exam multiple choice questions
• Understanding functions is crucial for the Create Performance Task

4.2 Next Class Preview (3 minutes)

Day 12 Topic: "Parameters and Return Values"

• Learning Objective: CRD-1.L - Use parameters and return values appropriately
• Activity: Practicing parameter passing and return values
• Homework: Think about a recent program you used. What functions did it employ?