Objectives (5 - 7 minutes)

1. Understand the difference between converging and diverging lenses, identifying their main characteristics and properties.
2. Develop the ability to identify, from a lens diagram, whether it is converging or diverging.
3. Apply the concepts learned in solving practical problems involving lenses, such as image formation and focal distance calculation.

Secondary objectives:

• Identify examples of converging and diverging lenses in everyday life.
• Understand how the curvature of a lens influences its optical properties.
• Develop problem-solving and critical thinking skills through the application of lens concepts.

The teacher should start the lesson by presenting the Learning Objectives to the students, explaining what they will achieve by the end of the lesson. It is important to emphasize that the secondary objectives are also important for a comprehensive understanding of the topic.

Introduction (10 - 15 minutes)

1. Review of previous concepts: The teacher should start the lesson with a brief review of geometric optics concepts, focus, and image formation, which were covered in previous lessons. This review is essential to ensure that students have the necessary knowledge to understand the concepts of converging and diverging lenses. During this review, the teacher can ask students questions to check their understanding of the reviewed concepts.

2. Problem situation: Next, the teacher should present two problem situations to the students. The first could be the formation of a sharp image in a camera, and the second could be the difficulty of seeing up close in some people due to presbyopia. The teacher should ask students what they think is happening in each of these situations and how optics might be involved.

3. Contextualization: The teacher should then contextualize the importance of studying lenses, explaining how they are used in various everyday technologies, such as glasses, contact lenses, microscopes, telescopes, cameras, among others. Additionally, the teacher can mention that the study of lenses is fundamental for understanding natural phenomena, such as the rainbow.

4. Gaining students' attention: To spark students' interest, the teacher can share some curiosities about lenses. For example, they can mention that the first converging lens was created by an Arab philosopher named Alhazen in the 11th century, and thanks to this invention, the first camera was developed. Another interesting curiosity is that some species of fish have such curious eyes that they can change the shape of their lenses to adapt to different light levels and focus at different distances.

By the end of the Introduction, students should be motivated and ready to start exploring the fascinating world of lenses!

Development (20 - 25 minutes)

1. Practical Activity 1: Building Lenses (10 - 12 minutes)

   • Necessary materials: PET bottles cut in half, black cardboard, adhesive tape, water, small flashlight.

   • Preparation: Before the lesson, the teacher should cut the PET bottles in half, creating two "lenses" of transparent plastic. Then, they should cover one of the halves with black cardboard to create a "diverging lens." The other half will be used as a "converging lens."

   • Activity development: Students, organized in groups of 4 or 5, should receive the materials and instructions for the activity. First, they should fill the "lens" with water and seal it with the other half of the bottle. Then, they should position the "lens" in front of the flashlight and observe the behavior of the light. With the "converging lens," the light should converge to a point, creating an image. With the "diverging lens," the light should spread out, not forming a sharp image. Students should record their observations and conclusions.

2. Practical Activity 2: Lenses in Real Life (10 - 12 minutes)

   • Necessary materials: Sunglasses and magnifying glass.

   • Activity development: The teacher should distribute the materials to the students and ask them to observe the lenses. Then, students should identify whether the lenses are converging or diverging and explain why. The teacher should circulate the room, assisting students and clarifying doubts. This activity will allow students to see the practical application of the studied concepts.

3. Problem-Solving Activity (5 - 7 minutes)

   • Necessary materials: Paper and pencil.

   • Activity development: The teacher should distribute a worksheet with problems involving converging and diverging lenses. Students should work individually or in small groups to solve the problems. After a set time, the teacher should review the answers with the class, explaining step by step the solution to each problem.

These practical and problem-solving activities will allow students to handle and observe the properties of lenses, deepening their understanding of the subject. Additionally, they promote teamwork, communication, and critical thinking.

Feedback (8 - 10 minutes)

1. Group Discussion (3 - 4 minutes): The teacher should organize a group discussion with all students. Each group should share their conclusions and solutions to the proposed problems. The teacher should ensure that all students have the opportunity to speak and that their contributions are valued.

2. Connection with Theory (2 - 3 minutes): After the discussion, the teacher should connect the practical activities with the theory. They should explain how the observations made by students during the practical activities reflect the theoretical concepts of converging and diverging lenses. The teacher can, for example, show how the curvature of the lens affects the light path and image formation, and how this relates to what was observed during the practical activity.

3. Individual Reflection (2 - 3 minutes): The teacher should propose that students individually reflect on what they learned in the lesson. To do this, they can ask the following questions:

   1. What was the most important concept you learned today?
   2. What questions remain unanswered?

   After a minute of reflection, students should share their answers with the class. The teacher should listen carefully to the students' answers, as they may indicate which concepts need to be reinforced in future lessons.

4. Teacher Feedback (1 minute): Finally, the teacher should give feedback to the students about the lesson. They should praise the students' effort and highlight the strengths of the lesson. Additionally, the teacher should reinforce the most important concepts and indicate the next steps in the study of lenses. For example, they can say that in the next lesson, they will explore the calculation of a lens's focal distance.

This Feedback is essential to consolidate students' learning and for the teacher to evaluate the effectiveness of their pedagogical approach. Additionally, it provides students with the opportunity to reflect on their own learning and express their doubts and difficulties.

Conclusion (5 - 7 minutes)

1. Summary of Contents (2 - 3 minutes): The teacher should start the Conclusion by summarizing the main points covered in the lesson. They should recall the concepts of converging and diverging lenses, the optical properties of these lenses, and how they are used in different everyday technologies. Additionally, the teacher should reinforce the skills developed by the students, such as the ability to identify the type of lens from a diagram and the ability to solve problems involving lenses.

2. Theory-Practice Connection (1 - 2 minutes): Next, the teacher should explain how the lesson connected theory and practice. They should recall the practical activities carried out, explaining how they allowed students to observe and handle the properties of lenses, and how these observations relate to theoretical concepts. Additionally, the teacher should highlight how problem-solving helped students apply theoretical concepts in a practical way.

3. Extra Materials (1 minute): The teacher should suggest some extra materials for students who want to deepen their knowledge about lenses. These materials can include educational videos, interactive simulations, complementary texts, among others. The teacher can, for example, suggest that students watch a video about the history of lenses and their importance for science and technology, or explore an online simulation that allows them to manipulate lenses virtually.

4. Relevance of the Subject (1 - 2 minutes): Finally, the teacher should emphasize the importance of studying lenses for students' daily lives. They can mention, for example, that knowledge about lenses is essential to understand how many technologies we use daily work, such as glasses, cameras, and cell phones. Additionally, the teacher can highlight that studying lenses can help students better understand the world around them, allowing them to appreciate natural phenomena like the rainbow in a deeper and more meaningful way.

The Conclusion is a crucial part of the lesson, as it allows students to consolidate what they have learned, make connections between different concepts, and understand the relevance of the subject to their lives. Additionally, by suggesting extra materials, the teacher encourages autonomous and in-depth study by the students.