AP® Computer Science A

Unit 2: Selection and Iteration

Lesson 5: Implementing Selection and Iteration Algorithms

Full Lesson Plan, Guided Notes, Slides & Homework

In this lesson, students will explore and implement common algorithmic patterns using while loops in Java. They will write and trace code for five foundational algorithms involving selection and iteration, helping them recognize when to apply loops and how to control repetition effectively in a program.

What’s Included:

• Detailed lesson plan
• Student guided notes
• Editable PowerPoint presentation
• Instructional video of the lesson
• Check for Understanding (CFU) with answer key
• "Unplugged" homework assignment to reinforce learning

Student Learning Objectives:

• Explain when and why to use a while loop.
• Use a while loop to repeatedly subtract, divide, or compare values until a condition is met.
• Write and trace five standard while loop algorithms, including checking divisibility, summing digits, counting occurrences, finding max/min values, and computing totals and averages.

Standards Alignment (AP CSA 2025 Framework):

2.9.A - Develop code for standard and original algorithms (without data structures) and determine the result of these algorithms.

Perfect For:

• New and experienced AP Computer Science A teachers
• Teachers introducing Java syntax and programming structure
• Schools using College Board’s official AP CSA framework

This resource is classroom-tested, student-friendly, and fully aligned to AP CSA expectations. Whether you're teaching this topic for the first time or want a polished, print-and-go lesson, this resource has you covered.

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Goldie's FULL CURRICULUM for AP Computer Science A

Goldie's Complete Unit Curricula:

Unit 1 – Using Objects and Methods

Unit 2 – Selection and Iteration

Unit 3 – Class Creation

Unit 4 – Data Collection

Goldie's Assessments:

Unit 1 – Using Objects and Methods | Goldie's Assessments

Unit 2 – Selection and Iteration | Goldie's Assessments

Unit 3 – Class Creation | Goldie's Assessments

Unit 4 – Data Collection | Goldie's Assessments

Goldie's Coding Projects & Activities:

Unit 1 – Using Objects and Methods | Goldie's Projects & Activities

Unit 2 – Selection and Iteration | Goldie's Projects & Activities

Unit 3 – Class Creation | Goldie's Projects & Activities

Unit 4 – Data Collection | Goldie's Projects & Activities

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Unit 1 Individual Lessons:

• Lesson 1 – Welcome to Java
• Lesson 2 – Variables and Data Types
• Lesson 3 – Expressions and Output
• Lesson 4 – Casting and Range of Variables
• Lesson 5 – Creating and Storing Objects
• Lesson 6 – Creating and Calling an Object's Methods
• Lesson 7 – String Manipulation
• Lesson 8 – Math Class

Unit 2 Individual Lessons:

• Lesson 1 – Conditional Statements
• Lesson 2 – Nested Selection
• Lesson 3 – Compound Boolean Expressions
• Lesson 4 – while Loops
• Lesson 5 – Implementing Selection and Iteration Algorithms
• Lesson 6 – for Loops
• Lesson 7 – Implementing String Algorithms
• Lesson 8 – Nested Iterations

Unit 3 Individual Lessons:

• Lesson 1 – Impacts of Program Design
• Lesson 2 – Program Design
• Lesson 3 – Classes and Constructors
• Lesson 4 – Accessor and Mutator Methods
• Lesson 5 – Class Variables and Methods
• Lesson 6 – References, Scope, and this

Unit 4 Individual Lessons:

• Lesson 1 – Ethical and Social Issues Around Data Collection
• Lesson 2 – Data Sets
• Lesson 3 – One Dimensional Arrays
• Lesson 4 – Array Traversals
• Lesson 5 – Implementing Array Algorithms
• Lesson 6 – Using Text Files
• Lesson 7 – Wrapper Classes
• Lesson 8 – ArrayList
• Lesson 9 – ArrayList Traversals
• Lesson 10 – Implementing ArrayList Algorithms
• Lesson 11 – 2D Arrays
• Lesson 12 – 2D Array Traversals
• Lesson 13 – Implementing 2D Array Algorithms
• Lesson 14 – Searching Algorithms
• Lesson 15 – Sorting Algorithms
• Lesson 16 – Recursion
• Lesson 17 – Tracing Recursive Output
• Lesson 18 – Recursive Searching and Sorting

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