Day 15: Program Development with Functions

Learning Objectives

• AAP-3.A: For procedure calls: Write statements to call procedures.
• AAP-3.B: Explain how the use of procedural abstraction manages complexity in a program.
• AAP-3.C: Develop procedural abstractions to manage complexity in a program by writing procedures.
• AAP-3.D: Select appropriate libraries or existing code segments to use in creating new programs.

Essential Questions

• How do we design modular programs using functions?
• How do functions work together to create complete programs?

Materials Needed

• Presentation slides on modular program design
• Programming environment
• Program design templates
• Mini-project requirements
• Exit ticket templates

Vocabulary

• Modular design
• Decomposition
• Top-down design
• Bottom-up design
• Function hierarchy
• Interface
• Implementation
• Abstraction
• Encapsulation

Procedure (50 minutes)

Opening (8 minutes)

1. Review and Connection (3 minutes)

   • Review libraries and APIs from previous lesson
   • Connect to today's focus on developing complete programs with functions

2. Warm-up Activity (5 minutes)

   • Present a complex programming task
   • Ask students to brainstorm how they might break it down into smaller functions
   • Discuss different approaches to decomposing the problem

Main Activities (32 minutes)

3. Lecture: Modular Program Design (12 minutes)

   • Explain the concept of modular program design:
     • Breaking down complex problems into smaller, manageable parts
     • Creating functions for each part
     • Combining functions to create a complete solution
   • Discuss approaches to program decomposition:
     • Top-down design: start with the big picture, break into smaller parts
     • Bottom-up design: build small components first, then combine
   • Explain function hierarchy and relationships:
     • Main functions and helper functions
     • Function dependencies
     • Function composition
   • Discuss best practices for modular design:
     • Appropriate function size and scope
     • Clear interfaces between functions
     • Minimizing dependencies
     • Reusing functions when possible
   • Explain how modular design supports:
     • Collaboration
     • Testing
     • Maintenance
     • Code reuse

4. Demo: Breaking Down Problems into Functions (8 minutes)

   • Walk through the process of designing a modular program:
     • Analyzing the problem requirements
     • Identifying major components
     • Defining function interfaces
     • Implementing individual functions
     • Combining functions into a complete program
   • Show examples of well-designed modular programs
   • Demonstrate how functions interact through parameters and return values
   • Highlight the benefits of the modular approach

5. Hands-on: Collaborative Program Development (12 minutes)

   • Students work in pairs or small groups
   • Assign each group a mini-project that requires multiple functions
   • Guide students through the development process:
     • Planning the program structure
     • Identifying necessary functions
     • Defining function interfaces
     • Dividing implementation responsibilities
     • Integrating functions into a complete program
   • Encourage students to document their functions
   • Circulate to provide guidance and feedback

Closing (10 minutes)

6. Activity: Mini-project Using Functions (5 minutes)

   • Groups continue working on their mini-projects
   • Focus on integrating functions and testing the complete program
   • Share and discuss different approaches to modular design
   • Highlight successful strategies and common challenges

7. Exit Ticket and Preview (5 minutes)

   • Students submit their modular programs with documentation
   • Preview that next class will focus on lists/arrays as data structures

Assessment

• Formative: Quality of program decomposition and function design
• Mini-Project: Effectiveness of modular design and function integration

Differentiation

For Advanced Students

• Assign more complex mini-projects requiring sophisticated decomposition
• Challenge them to optimize their design for reusability
• Introduce advanced concepts like higher-order functions

For Struggling Students

• Provide more structured guidance on program decomposition
• Offer function templates or starter code
• Focus on clearer function interfaces

Homework/Extension

• Complete the mini-project if not finished in class
• Refactor a previously written program to use a more modular design
• Research modular design patterns in professional software development

Teacher Notes

• Emphasize that modular design is a fundamental software engineering principle
• Watch for overly complex function interfaces or dependencies
• Make connections to real-world software development practices
• Consider discussing how modular design supports team collaboration
• Remind students that the AP Create Performance Task will require good program organization
• This concludes Week 3 of the unit