Objectives (5 - 7 minutes)

1. Introduce the concept of value equivalence, specifically discount and change, in a practical and playful way to elementary school students.
2. Explore problem situations involving the application of these concepts, stimulating logical thinking and the resolution of everyday math problems.
3. Develop mental calculation skills, encouraging students to perform simple mathematical operations (addition and subtraction) efficiently and accurately.

Introduction (10 - 12 minutes)

1. The teacher starts the lesson by reminding students of the basic concepts of addition and subtraction, which are fundamental to understanding the equivalence of values, discount, and change. This can be done through a quick review using simple examples from students' daily lives, such as adding or subtracting the number of students present in the classroom, the number of pencils in a box, etc.

2. Next, the teacher presents two problem situations that will serve as the basis for introducing the concept of discount and change:

   • Situation 1: 'Imagine you go to a candy store and the owner gives a special discount to each student. How can you find out how much the candy costs with the discount?'
   • Situation 2: 'Now, imagine you go to the school cafeteria and buy a snack that costs $5.00. You give a $10.00 bill to the cafeteria lady. How much change should you receive?'

3. The teacher contextualizes the importance of the subject, explaining that mathematics is present in various situations in our daily lives, such as in purchases, snack time, at the supermarket, etc. He emphasizes that understanding the concept of discount and change is essential to know if we are paying the right price for something and also to check if the change is correct.

4. To arouse students' curiosity, the teacher can share two curiosities related to the subject:

   • Curiosity 1: 'Did you know that discount math is used all over the world? It's true, in all places where we shop, discount math is the same.'
   • Curiosity 2: 'And did you know that change math was one of the first things people learned to do with numbers? A long time ago, when there was no money, people exchanged things with each other. And to know if the change was correct, they used change math.'

Development (20 - 25 minutes)

Activity 1: 'The Discount Shop' (10 - 12 minutes)

1. The teacher organizes students into small groups of up to 5 members and presents them with 'The Discount Shop.' For this, the teacher can bring some simple items (such as colored pencils, erasers, small toys, etc.) and label them with various prices.

2. Each group receives a fictional amount of money (which can be represented by paper notes and coins) and must choose one or more items to buy. The groups' task is to calculate the total purchase value considering a discount determined by the teacher.

3. The teacher circulates around the room, assisting the groups when necessary, and encourages discussion among students on how to arrive at the correct value.

4. At the end of the activity, the teacher facilitates a brief discussion in the classroom, asking each group what the total value of their purchase was and what the discount amount applied was. This helps reinforce the concept of discount and the importance of accurate calculation.

Activity 2: 'The Cafeteria and the Change' (10 - 12 minutes)

1. After the previous activity, the teacher proposes the situation of 'The Cafeteria and the Change.' Again organized in groups, students receive a card with a snack and a corresponding value for that snack.

2. The goal is to simulate the purchase of the snack in the cafeteria. The group must give the 'cashier' (a student designated by the teacher) a bill or a set of coins, representing the payment.

3. The 'cashier' then calculates the change and returns it to the group, checking if the amount is correct.

4. The teacher circulates around the room during the activity, observing and assisting the groups, if necessary.

5. At the end of the activity, the teacher can propose a challenge: 'Which group can, in less time, buy the snack and receive the change correctly?' This healthy competition can encourage students to work together more efficiently.

Extra Activity: 'The Grocery Store Change' (5 - 6 minutes)

1. To conclude the practical part of the lesson, the teacher proposes an extra activity, 'The Grocery Store Change.'

2. Students, once again organized in groups, receive a shopping list with different items and prices. Each group receives a fictional amount of money and must calculate the total purchase value, pay the 'cashier,' and receive the change.

3. The teacher can challenge the group that manages to buy all the items on the list and receive the change correctly in less time to win a 'little prize' (it can be a candy, a special drawing on the board, etc.).

4. At the end of the activity, the teacher reinforces the importance of accurate and efficient calculation to solve everyday problems.

These practical activities allow students to experience in practice what discount and change are, helping to consolidate the concept of value equivalence in a playful and fun way.

Feedback (8 - 10 minutes)

1. The teacher gathers all students in a large circle to promote a group discussion about the solutions found for the activities. He can start by asking each group what they learned from the 'The Discount Shop' activity and if they were able to understand how to calculate the discount.

2. Next, the teacher asks the students who participated in the 'The Cafeteria and the Change' activity if they had any difficulty calculating the change and how they solved that difficulty. He can also ask the other students what they observed during the activity.

3. The teacher then provides a theoretical review of the content, highlighting the main points learned during the practical activities. He can use the board to draw and write the calculations that were made during the activities, reinforcing the concept of discount and change.

4. During the review, the teacher should pose some questions to the students to verify if they understood the concept of value equivalence, discount, and change. For example: 'Why is it important to know how to calculate the discount when making a purchase?' or 'Why is it important to know how to calculate the change?' Students can respond individually or in groups.

5. Finally, the teacher concludes the lesson by asking students to reflect on what they have learned. He can ask two simple questions for students to answer mentally: 'How can you use what you learned today in your lives?' and 'What did you enjoy learning the most today?'

6. The teacher reminds students that mathematics is an important tool for solving everyday problems and that they can practice what they have learned at home, in real situations involving purchases and change, for example. He can also suggest some extra activities for students to practice what they have learned, such as solving math problems involving discount and change.

This feedback stage is essential to consolidate students' learning, allowing them to reflect on what they have learned and how they can apply this knowledge in their lives. Additionally, it provides the teacher with the opportunity to assess the effectiveness of the lesson and identify possible areas for improvement for future classes.

Conclusion (5 - 7 minutes)

1. The teacher begins the conclusion by reviewing the main points covered during the lesson. He reinforces the concept of value equivalence, discount, and change, reminding students that these are fundamental concepts for solving everyday math problems. For example, he can ask students: 'Remember, what is a discount?' and 'What is the importance of knowing how to calculate the change?'

2. Next, the teacher highlights how the lesson connected theory to practice. He emphasizes that through playful activities, students were able to apply the mathematical concepts learned in a fun and meaningful way. For example, he can say: 'Did you see how discount and change math are important in our daily lives? With these calculations, we can know if we are paying the right price for something and we can also check if the change is correct.'

3. The teacher then suggests some materials for home study. He can recommend textbooks that address the topic of discount and change clearly and accessibly for students. Additionally, he can suggest educational websites with interactive math games involving discount and change, so that students can practice what they have learned in a fun way.

4. The teacher concludes the lesson by emphasizing the importance of the subject for students' daily lives. He explains that discount and change math is used in various everyday situations, such as in purchases, snack time, at the supermarket, etc. He encourages students to observe and practice these calculations in real situations, so they can become more efficient and confident in their transactions.

5. Finally, the teacher thanks everyone for their participation and reinforces that to learn mathematics (and any other subject), it is important to practice and always be open to new challenges. He reminds students that they are capable of solving math problems, and that mathematics is a powerful tool that can help them in many life situations.

This conclusion serves to summarize the main points of the lesson, reinforce the connection between theory and practice, and motivate students to continue learning and practicing mathematics. Additionally, it provides students with a starting point to deepen their knowledge on the subject at home, through study materials recommended by the teacher.