Developing a Program

Lesson Overview

Unit: Python Programming Basics
Lesson Number: 6 of 6
Key Stage: KS4/KS5 (Years 10-12)
Curriculum Link: A-Level Computer Science – Computational Thinking, Programming & Problem Solving (AQA, OCR, Edexcel)
Lesson Duration: 45 minutes
Class Size: 15 students

Learning Objectives

By the end of the lesson, students will be able to:

• Apply Python programming concepts to develop a functional program.
• Implement variables, user input, and arithmetic operations in a practical coding project.
• Debug and refine their code through problem-solving techniques.
• Evaluate their own and peers' programs using structured feedback.

Required Materials

• Computers with Python installed (IDLE or PyCharm recommended)
• Projector and whiteboard
• Starter code template (provided by teacher)

Lesson Structure

0-5 Minutes: Starter Activity – Debug the Code!

1. Display a short, buggy piece of Python code on the board:

   user_name = input("Enter your name: ")  
   age = input("Enter your age: ")  
   future_age = age + 10  
   print("In 10 years, you will be " + future_age)  
   

2. Ask students to work in pairs to identify and correct the error.

3. Discuss the importance of data types and conversions.

4. Introduce today's goal: building a functional Python program from scratch.

5-15 Minutes: Teacher-Led Demonstration

1. Problem Breakdown: Explain that students will create a simple "Tip Calculator" that asks the user for a bill amount, tip percentage, and calculates the total cost.

2. Step-by-Step Walkthrough: Live-code the first few steps on the board:

   bill_amount = float(input("Enter the bill amount: £"))  
   tip_percentage = float(input("Enter the tip percentage: "))  
   total_tip = (tip_percentage / 100) * bill_amount  
   total_amount = bill_amount + total_tip  
   print(f"Your total bill, including tip, is: £{total_amount:.2f}")  
   

3. Pause after each step and ask students to predict what will happen when the code is run.

4. Run the code to test output, highlighting how user input impacts calculations.

15-35 Minutes: Independent Project – Build Your Own Calculator

1. Task Instructions:

   • Each student will design their own variation of a calculator program.
   • Possible ideas:
     • A discount calculator for shopping
     • A basic BMI calculator
     • A currency converter
   • The program must include user input, variables, and arithmetic operations.

2. Support & Guidance:

   • Encourage students to break the task into smaller steps:
     • Plan inputs/outputs
     • Write pseudocode
     • Code incrementally, testing frequently
   • Circulate the room, assisting with debugging issues.

35-40 Minutes: Peer Review & Refinement

1. Pair up students to review each other’s code.
2. Provide a checklist for structured feedback:
   • Does the program run successfully?
   • Is the code well-structured and readable?
   • Any enhancements or additional features possible?
3. Students refine their program based on feedback.

40-45 Minutes: Reflection & Plenary Discussion

• Ask students to share their calculators and describe how they approached problem-solving.
• Discuss common challenges and debugging strategies.
• Tie the lesson back to real-world applications (e.g., financial apps, cost estimators).
• End with a question: “What would you add if you had more time?”

Homework/Extension Task

• Challenge: Modify the program to handle input errors (e.g., user enters text instead of a number).
• Research task: Investigate how Python is used in financial modelling.

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Assessment & Differentiation

✅ Assessment:

• Formative: Teacher observation, questioning, and peer assessment feedback.
• Summative: Completed Python program functionality and coding style.

✅ Differentiation:

• Support: Provide a code scaffold for struggling students.
• Challenge: Encourage advanced students to add currency formatting, additional user prompts, or graphical elements using Tkinter.

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This lesson ensures students consolidate their Python skills in a practical setting, fostering problem-solving abilities and computational thinking essential for KS4 & KS5 curricula.