Objectives (5 - 7 minutes)

1. Understand the concept of percentage increases and discounts: The teacher must ensure that students understand the concept of percentage and how it applies to increases and discounts. This includes the ability to quickly calculate the value of an increase or discount on a price, salary, or any other quantity.

2. Apply knowledge in practical situations: Students should be able to apply what they have learned about percentage increases and discounts in real-world situations. This may include determining the price of an item after a discount, calculating a salary increase, or understanding how taxes can affect income.

3. Develop critical thinking and problem-solving skills: In addition to learning the necessary formulas to calculate percentage increases and discounts, students should be able to think critically about how and when to apply them. This requires the ability to analyze a problem, identify the appropriate solution strategy, and execute it correctly.

   Secondary objectives:

   • Develop teamwork and communication skills: By working in groups to solve problems, students will have the opportunity to enhance their collaboration and communication skills.

   • Promote autonomy and responsibility for their own learning: Through the flipped classroom model, students will be encouraged to take responsibility for their own learning by exploring the content before class and coming prepared to discuss and apply what they have learned.

Introduction (10 - 15 minutes)

1. Review of previous concepts:

   • The teacher should start the lesson by reviewing the concepts of percentage and proportion, which are fundamental to understanding the lesson's topic. This can be done through a brief quiz or classroom discussion to assess students' understanding of these concepts.

2. Initial problem situations:

   • The teacher can present two problem situations to students to arouse interest and curiosity about the lesson's topic. For example, they can ask: "If a product costs R$ 100 and we have a 20% discount, what will be the new price?" or "If an employee receives a 10% salary increase, how much will they receive monthly?".

3. Contextualization of the topic's importance:

   • The teacher should then explain the practical importance of the subject, showing how calculating percentage increases and discounts is useful in everyday life, both for consumers (when calculating the price of a discounted product) and for workers (when calculating the impact of a salary increase or discount).

4. Introduction of the topic in an engaging way:

   • To capture students' attention, the teacher can introduce the topic with interesting facts or applications. For example, they can mention that percentage discounts are used not only in commerce but also in areas such as finance (to calculate the Return on Investment) and medicine (to calculate the effectiveness of a treatment).

   • Additionally, they can present a historical fact about the origin of percentages, explaining that the word "percent" comes from the Latin "per centum," which means "per hundred." Thus, when we say that something has a 20% discount, we are saying that the price has been reduced by 20 per every 100.

Development (20 - 25 minutes)

1. Activity 1 - "The Big Sale" (10 - 12 minutes)

   • Context: The teacher should present a situation where a department store is having a big sale, offering discounts of up to 50% on various products. Students, divided into groups of 4 to 5, will be challenged to calculate the new price of each item after the discount, using the concept of percentage.

   • Materials: The teacher should provide students with a list of products with their original prices and the discount percentage. Additionally, each group should have a calculator and a sheet of paper to record the calculations.

   • Step by step:

     1. The teacher distributes the materials and explains the problem situation.
     2. Students, in their groups, choose a product from the list to start the activity.
     3. Using the discount formula (Discount value = Original price * (Discount percentage / 100)), students calculate the discount value and the new price of the product.
     4. Students record the calculations and discuss the result in their groups.
     5. The teacher circulates around the room, assisting groups that encounter difficulties and checking the correctness of the calculations.
     6. Groups present their answers to the class, explaining how they arrived at the result.

2. Activity 2 - "Salary Negotiation" (10 - 12 minutes)

   • Context: The teacher should present a situation where an employee is negotiating a salary increase with their boss. Students, still in their groups, will be challenged to calculate the employee's new salary after the increase, using the concept of percentage.

   • Materials: The teacher should provide students with the employee's current salary and the proposed percentage increase. Additionally, each group should have a calculator and a sheet of paper to record the calculations.

   • Step by step:

     1. The teacher distributes the materials and explains the problem situation.
     2. Students, in their groups, discuss the situation and choose a salary and a percentage increase to start the activity.
     3. Using the increase formula (Increase value = Current salary * (Percentage increase / 100)), students calculate the increase value and the employee's new salary.
     4. Students record the calculations and discuss the result in their groups.
     5. The teacher circulates around the room, assisting groups that encounter difficulties and checking the correctness of the calculations.
     6. Groups present their answers to the class, explaining how they arrived at the result.

3. Discussion and reflection: (5 - 6 minutes)

   • After completing the activities, the teacher should lead a classroom discussion so that students can reflect on what they have learned. The teacher can ask questions like: "What was the most important concept you learned today?" and "How can you apply what you learned about percentage increases and discounts in your daily lives?".

   • Additionally, the teacher should clarify any remaining doubts and reinforce the key concepts of the lesson.

Return (8 - 10 minutes)

1. Group Discussion (3 - 4 minutes)

   • The teacher should ask each group to share their solutions or conclusions from the activities. Each group will have a maximum of 3 minutes to present. During the presentations, the teacher should encourage other students to ask questions and make comments, promoting a collaborative learning environment.

2. Connection with Theory (2 - 3 minutes)

   • After the presentations, the teacher should revisit the theoretical concepts covered in the lesson, making a connection with the solutions presented by the groups. It is important for the teacher to highlight how the theory was applied in practice, reinforcing the importance of the content learned.

3. Individual Reflection (2 - 3 minutes)

   • The teacher should suggest that students reflect individually for a minute on the following questions:
     1. What was the most important concept you learned today?
     2. What questions have not been answered yet?
   • After the reflection, students can share, if they wish, their answers with the class. The teacher should pay attention to unanswered questions, as they may indicate which concepts need to be reinforced in future lessons.

4. Feedback and Closure (1 - 2 minutes)

   • Finally, the teacher should provide overall feedback on the lesson, highlighting the positives and areas that still need improvement. The teacher should also encourage students to continue studying the subject and to ask questions in the next class.

   • The teacher should then conclude the lesson, reinforcing the importance of the content learned and how it applies to everyday situations. For example, the teacher can give examples of how calculating percentage increases and discounts can be useful when shopping, budgeting, or negotiating a salary.

Conclusion (5 - 7 minutes)

1. Summary of Contents (1 - 2 minutes)

   • The teacher should start the Conclusion by summarizing the main contents covered in the lesson. This includes the definition of percentage, the formulas for calculating percentage increases and discounts, and the application of these concepts in real situations. The teacher can ask students to participate in the summary, recalling what they learned and clarifying any final doubts.

2. Connection between Theory, Practice, and Applications (1 - 2 minutes)

   • Next, the teacher should highlight the connection between theory, practice, and the applications of the content. The teacher can review the activities carried out, explaining how they allowed students to apply theory in real-world situations. Additionally, the teacher can provide additional examples of how knowledge of percentage and percentage increases/discounts can be useful in various situations, from buying a discounted product to negotiating a salary increase.

3. Additional Materials (1 - 2 minutes)

   • The teacher should then suggest additional materials for students to deepen their understanding of the subject. This may include books, articles, videos, educational websites, and extra exercises. For example, the teacher may recommend a website with interactive math games involving percentage calculations, or an explanatory video on how to calculate percentage discounts.

4. Importance of the Subject in Daily Life (1 minute)

   • Finally, the teacher should reinforce the importance of the content learned in daily life. The teacher can provide additional examples of how the concepts of percentage and percentage increases/discounts are used in various practical situations. This can help students realize the relevance of what they have learned and feel more motivated to apply their knowledge in the real world.

5. Lesson Closure (30 seconds)

   • To conclude the lesson, the teacher can thank the students for their participation, emphasize the importance of reviewing the content and preparing for the next class, and wish everyone a good day.