Objectives (5 - 7 minutes)

1. Understand the concept of subtraction: Students should be able to understand that subtraction is a mathematical operation that represents the action of taking away one quantity from another. They should be able to relate subtraction to everyday situations.

2. Identify the terms of subtraction (minuend, subtrahend, and difference): Students should learn to identify the three essential terms in a subtraction: the minuend (the starting number), the subtrahend (the quantity to be taken away), and the difference (the result of the operation).

3. Use subtraction strategies: Students should be able to apply different subtraction strategies, such as counting down, taking away, and complement, to solve simple subtraction problems.

Secondary Objectives:

1. Develop logical reasoning skills: Through solving subtraction problems, students should be encouraged to develop logical reasoning skills, such as the ability to analyze, deduce, and solve problems systematically.

2. Promote interest and curiosity in mathematics: The ultimate goal is to spark students' interest in mathematics, showing them how subtraction is present in their daily lives and how it can be used to solve real problems.

Introduction (10 - 12 minutes)

1. Concept review: The teacher starts the lesson by reviewing the concepts of addition, which have been previously covered. They can propose simple problem situations involving addition for students to recall and apply what they have learned. For example, if the class has 25 students and 10 more arrive, how many students are there now in the room? Or if a student had 5 pencils and received 3 more, how many pencils do they have now?

2. Everyday situations: The teacher then proposes two everyday situations that can be solved using subtraction. The first situation could be: 'If you had 10 chocolates and ate 3, how many chocolates do you have now?' The second situation could be: 'If you had $20.00 and spent $7.00, how much money do you have now?'

3. Contextualization of the importance of subtraction: The teacher explains that subtraction is an important tool in our daily lives, as it helps us solve problems involving taking away or reducing quantities. They can give examples of real situations, such as when we go to the supermarket and need to calculate change, or when we share toys or sweets with friends.

4. Capturing students' attention: To spark students' interest, the teacher can share two curiosities about subtraction. The first curiosity could be that subtraction is one of the four basic operations in mathematics, and that all other operations (addition, multiplication, and division) are based on it. The second curiosity could be that subtraction is the inverse operation of addition, just as division is the inverse operation of multiplication.

5. Introduction of the topic: Finally, the teacher introduces the topic of the lesson: 'Today we will learn about subtraction. We will understand what subtraction is, how it works, and how we can use this operation to solve problems in our daily lives.' They can then hand out to each student a sheet with some simple subtraction exercises for them to practice the new skill they will learn.

Development (20 - 25 minutes)

1. Theory Explanation: The teacher starts the theoretical part of the lesson by explaining what subtraction is. They can use the example of a pizza to make the concept more concrete. For example, if we had 8 slices of pizza and ate 3, now we have 8-3=5 slices. The teacher then states that 8 is the minuend, 3 is the subtrahend, and 5 is the difference. They can reinforce these terms with other examples, such as: if we had 10 toys and lost 2, now we have 10-2=8 toys.

2. Identification of subtraction terms: Next, the teacher presents the identification of the terms of subtraction, focusing on the importance of each one. They can use posters with examples and ask for students' help to identify the minuend, subtrahend, and difference. For example, on a poster it says '15 - 7 = 8', the teacher asks: 'Who can tell me what the minuend is in this subtraction? And the subtrahend? And the difference?'

3. Subtraction Strategies: After the theory presentation, the teacher explains some strategies that students can use to solve subtraction problems. They can start with the strategy of counting down, which is the simplest and students may already be familiar with. For example, if the subtraction is 8-3, the teacher can say: 'Let's start with 8 and count back 3 numbers: 8, 7, 6. The answer is 6.'

4. Subtraction Strategies - 'Taking Away': Next, the teacher can introduce the 'taking away' strategy. For example, if the subtraction is 8-3, the teacher can say: 'We can imagine that we have 8 toys and want to give 3 to a friend. If we take away 3 toys from the 8, how many toys do we have left? The result is 5.'

5. Subtraction Strategies - 'Complement': Finally, the teacher can teach the 'complement' strategy. For example, if the subtraction is 8-3, the teacher can say: 'We can think that we want to find a number that, when added to 3, gives 8. This number is the complement of 3 in relation to 8. If 3 + ? = 8, then ? = 8-3, which is equal to 5. So the answer is 5.'

6. Application of Strategies: After explaining each strategy, the teacher can propose subtraction problems for students to apply the learned strategies. The problems should be simple and contextualized, such as: 'You had 5 balls and gave 2 to your friend. How many balls do you have now?' or 'If you had 10 chocolates and ate 3, how many chocolates do you have now?'

7. Practice Exercises: To conclude the development part, the teacher can propose a series of subtraction exercises for students to practice all the strategies they have learned. The exercises should vary in difficulty level, so students can progress in their subtraction skills.

Throughout the development, the teacher should be attentive to clarify any doubts students may have and to correct any conceptual errors that may occur. They should also encourage active student participation by asking questions and requesting students to explain the strategies they are using to solve subtraction problems.

Return (8 - 10 minutes)

1. Group Discussion: The teacher gathers all students in a large circle and promotes a group discussion. They can start by asking each student how they solved one of the proposed subtraction exercises. The teacher should encourage students to explain the strategies they used, if they encountered any difficulties, and how they overcame them. During the discussion, the teacher should ask questions to check students' understanding and correct any misconceptions that may arise. This is an opportunity for students to learn from each other and for the teacher to assess each student's progress.

2. Connection with Theory: After discussing the exercise solutions, the teacher revisits the theory of subtraction and connects it with the strategies students used. For example, they can say: 'Do you remember we talked about the counting down strategy? That's what Maria used to solve the first exercise. And do you remember the taking away strategy? That's what João used to solve the second exercise. And the complement strategy? Who used it?'

3. Reflection on Learning: Finally, the teacher suggests that students reflect on what they learned in the lesson. They can ask two simple questions: 'What did you find easiest about subtraction? And what did you find most difficult?' Students can respond by raising their hand or expressing verbally. The teacher should value all answers and reinforce that subtraction is a skill that can be improved with practice and persistence.

4. Closure: To conclude the lesson, the teacher thanks everyone for their participation and effort. They reinforce that subtraction is an important skill that students will use in many everyday situations. They can suggest that students practice subtraction at home by solving some simple problems. The teacher can also recommend additional materials, such as games, apps, or educational websites that help reinforce the learning of subtraction.

Throughout the return, the teacher should maintain a welcoming and positive attitude, valuing students' efforts and progress. They should emphasize that subtraction is a skill that everyone can learn and that the most important thing is the learning process, not just the final result.

Conclusion (5 - 7 minutes)

1. Concept Review: The teacher starts the conclusion of the lesson by briefly reviewing the main concepts covered. They reinforce that subtraction is a mathematical operation that represents the action of taking away one quantity from another. They review the definition of minuend (the starting number), subtrahend (the quantity to be taken away), and difference (the result of the operation). The teacher can also recap the subtraction strategies learned, such as counting down, taking away, and complement.

2. Connection between theory and practice: Next, the teacher highlights how the lesson connected the theory of subtraction with practice. They remind students that, although mathematics may sometimes seem abstract, it is always present in our lives and can be used to solve everyday problems. The teacher reinforces that by learning subtraction strategies, students are acquiring an important tool to solve quantity problems.

3. Additional Materials: The teacher suggests some additional materials for students who wish to deepen their knowledge of subtraction. They can recommend children's math books that explore the concept of subtraction in a playful and interactive way. Additionally, the teacher can indicate educational websites and apps that offer fun subtraction games and activities for students to practice at home.

4. Importance of the subject: Finally, the teacher emphasizes the importance of subtraction in everyday life. They mention that subtraction is an essential skill in various situations, such as calculating change in a purchase, sharing toys or sweets among friends, or solving simple everyday problems. The teacher encourages students to continue practicing subtraction and to realize how it is present in their routine.

5. Closure: The teacher concludes the lesson by thanking everyone for their participation and dedication. They reinforce that subtraction is a subject that will be revisited and deepened in the upcoming lessons, and that students will have many opportunities to practice and improve their subtraction skills. Finally, they reiterate the importance of not giving up in the face of challenges and of persisting in practice to become increasingly skilled in mathematics.