Objectives (5 - 7 minutes)

1. Understand the concept of operations with natural numbers: The main objective is for students to understand what mathematical operations are (addition, subtraction, multiplication, and division) and how they apply to natural numbers.

2. Apply operations in problem-solving situations: After theoretical understanding, students should be able to apply these operations in practical situations, such as everyday math problems.

3. Develop problem-solving skills: In addition to understanding the theory and applying the operations, students should enhance their problem-solving skills, thinking critically and logically to arrive at the correct answers.

Secondary objectives:

• Foster active participation: Encourage student participation during the class, promoting discussions and clarifying doubts, so they feel involved and motivated in the learning process.

• Stimulate critical thinking: In addition to solving math problems, students should be encouraged to think about the problem-solving process, evaluating possible strategies and reflecting on the logic behind the operations.

Introduction (10 - 15 minutes)

1. Review of previous concepts: The teacher should start by reviewing the basic concepts of natural numbers, including what they are, how they are represented, and how they are ordered. Additionally, it is important to review the properties of addition and subtraction, which will be fundamental for understanding the operations. (3 - 5 minutes)

2. Initial problem-solving situations:

   • Problem 1: "If João had 5 apples and ate 3, how many apples does he have now?"
   • Problem 2: "Ana wants to divide 10 candies equally between her and her friends. If she has two more friends, how many candies will each one have?"

   The teacher should propose these problems to the students and encourage them to think of possible solutions. (3 - 5 minutes)

3. Contextualization: The teacher should explain that operations with natural numbers are very useful and applied in various everyday situations, such as when shopping, dividing food, calculating distances, among others. This can help spark students' interest by showing the relevance of the subject. (2 - 3 minutes)

4. Introduction to the topic: To spark students' interest, the teacher can present two curiosities/stories related to the topic:

   • Curiosity 1: The teacher can explain that operations with natural numbers are very ancient and were developed by various civilizations, such as the Egyptians, Babylonians, and Greeks, to solve everyday problems and perform mathematical calculations.
   • Curiosity 2: The teacher can talk about the "Goldbach's Conjecture," a famous mathematical question involving the sum of prime numbers. Although it is a complex problem, its resolution depends on the understanding and application of operations with natural numbers. (2 - 4 minutes)

Development (20 - 25 minutes)

1. Theory - Operations with Natural Numbers (10 - 12 minutes):

   1.1. Addition and Subtraction: The teacher should explain the concept of addition and subtraction, showing that addition is the operation that combines two or more numbers and subtraction is the operation that takes one number away from another. It is important to reinforce that addition is an operation that results in a larger number, while subtraction results in a smaller number.

   1.2. Multiplication and Division: Next, the teacher should introduce the concept of multiplication and division, highlighting that multiplication is an addition of equal parts and division is the equitable distribution of a whole into equal parts.

   1.3. Order of Operations: The teacher should explain the order of operations, reinforcing that in a numerical expression, operations must be performed in the following order: parentheses, exponentiation and root, multiplication and division (from left to right), and addition and subtraction (from left to right).

2. Practice - Examples and Exercises (10 - 13 minutes):

   2.1. Solving Examples: The teacher should present some examples of operations with natural numbers and solve them step by step, explaining each stage of the process.

   2.2. Solving Exercises: Next, the teacher should propose some exercises for the students to solve, applying what they have learned. The teacher should move around the classroom, assisting students who encounter difficulties and correcting the exercises.

3. Discussion and Reflection (2 - 3 minutes):

   3.1. Discussion: The teacher should promote a brief discussion about operations with natural numbers, asking students what they have learned and what were the most challenging parts of the lesson.

   3.2. Reflection: The teacher should encourage students to reflect on the importance of operations with natural numbers in their lives and how they can be applied in everyday situations.

Note: The time for each stage may vary according to the class's pace and the content's complexity. The teacher should adapt the lesson plan as needed.

Return (8 - 10 minutes)

1. Review and Summary (3 - 4 minutes): The teacher should start this stage by reviewing the main points covered in the lesson, reinforcing the concepts of addition, subtraction, multiplication, and division of natural numbers. It is important for the teacher to ask questions to assess students' understanding and encourage them to make comments or clarify doubts.

2. Connection to Practice (2 - 3 minutes): The teacher should then connect the theory learned with practical situations in everyday life. For this, students can be asked to think of examples of how operations with natural numbers can be used in real situations. For example, when dividing a pizza among friends (division), when adding up the total sales of a store (addition), when calculating the change from a purchase (subtraction), or when calculating the price of 3 candy packs if each pack costs $2 (multiplication).

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

   1. What was the most important concept learned today?
   2. What questions have not been answered yet?

   Students should write down their answers in a notebook or on a piece of paper. The teacher can move around the classroom to ensure that everyone is reflecting and to help those who have difficulty answering the questions.

4. Sharing Reflections (1 - 2 minutes): Finally, the teacher should invite some students to share their reflections with the class. This can help consolidate learning and clarify any remaining questions.

5. Closure (1 minute): The teacher should end the lesson by thanking everyone for their participation and encouraging students to continue studying and practicing operations with natural numbers. The teacher can also suggest some extra activities for students who wish to deepen their knowledge on the subject.

Note: The time for each stage may vary according to the class's pace and the content's complexity. The teacher should adapt the lesson plan as needed.

Conclusion (5 - 7 minutes)

1. Recapitulation of concepts (2 - 3 minutes): The teacher should recap the main points covered in the lesson, emphasizing the concept and application of operations with natural numbers. It is important for students to understand the difference between addition, subtraction, multiplication, and division, and how each of these operations applies to everyday situations.

2. Connection between theory, practice, and applications (1 - 2 minutes): The teacher should reinforce how the lesson connected theory (the concepts and principles of operations), practice (the examples and exercises solved), and applications (everyday situations where operations are used). This will help students understand the relevance of what they learned and how they can apply this knowledge in their lives.

3. Extra Materials (1 minute): The teacher can suggest some extra materials for students who wish to deepen their knowledge of operations with natural numbers. This may include math books, educational websites, explanatory videos, and math games. The teacher should also provide extra exercises for students to practice at home.

4. Importance of the subject (1 minute): Finally, the teacher should emphasize the importance of operations with natural numbers in everyday life. For example, the teacher can mention that these operations are essential for solving more complex math problems, for understanding scientific phenomena, and for making decisions in various areas of life. This can motivate students to dedicate more to their studies and to value what they are learning.

Note: The time for each stage may vary according to the class's pace and the content's complexity. The teacher should adapt the lesson plan as needed.