AP CSP Day 19 - 2D Lists and Nested Loops

Course Information

• Course: AP Computer Science Principles
• Unit: Big Idea 1 - Creative Development (CRD)
• Lesson: Day 19 (50 minutes)
• Learning Objective: CRD-1.S - Use 2D lists and nested loops appropriately

Learning Objectives

Primary Goals

Students will be able to:

1. Understand the concept of 2D lists and nested loops in programming
2. Create programs using 2D lists and nested loops effectively
3. Test and refine program logic involving 2D lists and nested loops
4. Analyze real-world scenarios that require 2D lists and nested loops

AP Exam Alignment

• Big Idea 1: Creative Development (10-13% of AP Exam)
• Essential Knowledge: CRD-1.S.1, CRD-1.S.2, CRD-1.S.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 traversing lists
• Introduce today's topic on 2D lists and nested loops

Student Activities:

• Think about: "What are some examples where we use 2D lists and nested loops in daily life?"

1.2 2D List and Nested Loop Examples Challenge (5 minutes)

Activity: "Identify the 2D List and Nested Loop"
Instructions:

• Groups of 4-6 students
• Identify 2D lists and nested loops in given scenarios
• Discuss the importance of 2D lists and nested loops

Purpose: Activate thinking about 2D lists and nested loops

Core Content Instruction (20 minutes)

2.1 What are 2D Lists and Nested Loops? (10 minutes)

Definition (CRD-1.S.1):

A 2D list is a list of lists, and nested loops involve placing one loop inside another.

Key Concepts:

• 2D list creation: my_2d_list = row1], [row2
• Nested loop traversal: for row in my_2d_list: for item in row:
• Accessing elements: my_2d_list[row_index][col_index]

Case Study: Using 2D lists and nested loops in a simple program

• Program: Print all elements of a matrix
• Traversal structure: for row in matrix: for item in row: print(item)

2.2 Common 2D List Operations (5 minutes)

Examples:

• Creation: my_2d_list = 1, 2], [3, 4
• Traversal: for row in my_2d_list: for item in row:
• Modification: my_2d_list[0][1] = 5

Discussion Questions:

1. What makes good 2D list usage?
2. Can you think of an example where 2D lists and nested loops are used in daily life?
3. Why are 2D lists and nested loops important in programming?

2.3 Advanced 2D List Concepts (5 minutes)

Why is it important?:

• Efficiency: Handling large datasets quickly
• Complexity: Solving more intricate problems

Discussion Questions:

1. How can we handle large datasets with 2D lists and nested loops?
2. Why is complexity important when using 2D lists and nested loops?

Hands-On Activity (15 minutes)

3.1 Group Project: Create a Program with 2D Lists and Nested Loops (15 minutes)

Activity: "Design a Program"
Instructions:

• Groups of 3-4 students
• Design a program that uses 2D lists and nested loops effectively
• Test the program for correctness
• Present the program to the class

Materials:

• **Program design worksheet
• **2D list and nested loop checklist

Learning Goals:

• **Understand 2D lists and nested loops
• **Create programs using 2D lists and nested loops effectively
• **Test program logic involving 2D lists and nested loops
• **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 2D lists and nested loops in programming
2. ✅ Creating programs using 2D lists and nested loops effectively
3. ✅ Testing and refining program logic involving 2D lists and nested loops
4. ✅ Analyzing real-world scenarios that require 2D lists and nested loops

AP Exam Connection:

• These concepts will appear in AP exam multiple choice questions
• Understanding 2D lists and nested loops is crucial for the Create Performance Task

4.2 Next Class Preview (3 minutes)

Day 20 Topic: "Other Collection Types"

• Learning Objective: CRD-1.T - Use other collection types appropriately
• Activity: Practicing collection type operations
• Homework: Think about a recent program you used. What 2D lists and nested loops did it employ?