Objectives (5 - 7 minutes)

1. Provide students with a clear understanding of the concept of addition, explaining that it is a mathematical operation that combines two or more numbers to obtain a total.

2. Teach students to identify the terms of an addition (numbers being added) and the result (the sum) in a practical and interactive way.

3. Help students develop addition skills, starting with simple one-digit additions and progressing to more complex additions with two or three digits.

The teacher should start the lesson by briefly reviewing students' prior knowledge of numbers and counting. Then, he should present the lesson objectives, explaining what students will learn and why it is important. The teacher should use simple and direct language, adapted to the students' level of understanding.

Introduction (10 - 15 minutes)

1. Counting and Numbers Review: The teacher should remind students about counting and the numbers they have already learned. He can ask questions like 'How many fingers do you have on one hand?' or 'How many students are in the classroom today?'. These questions will help students recall counting and the importance of numbers.

2. Problem Situations: The teacher should then present two problem situations that encourage students to think about addition. For example, 'If you have 2 apples and I give you 3 more, how many apples do you have in total?' or 'If you have 4 friends and each of you gets 1 more balloon, how many balloons do you all have in total?'. These situations will help contextualize addition and show students how it is relevant in their daily lives.

3. Everyday Application: The teacher should then explain how addition is used in everyday life. For example, to count the number of toys, to calculate the sum of scores in a game, or to divide a quantity of candies among friends. The teacher may even bring real objects to the classroom and ask students to add them up, making learning more concrete and tangible.

4. Topic Introduction: Finally, the teacher should introduce the topic of addition in a more formal way, explaining that addition is a way to combine two or more numbers to obtain a total. He can illustrate this with simple examples, such as '2 + 3 = 5' or '4 + 1 = 5'. The teacher should emphasize that addition is one of the most basic operations in mathematics and is used in many everyday situations.

The introduction should be interactive and engaging, with the teacher encouraging students to participate and think of solutions to the problem situations. The teacher should use simple and direct language, adapted to the students' level of understanding, and should be attentive to clarify any doubts that may arise.

Development (20 - 25 minutes)

1. Explanation of Simple Addition (10 - 12 minutes)

   1.1. Addition Theory: The teacher should start by explaining the theory of addition in a simple and practical way. He should emphasize that addition is a way to combine two or more numbers to obtain a total. For example, '2 + 3 = 5' means that when you have 2 things and add 3 more, you end up with a total of 5.

   1.2. Addition Terms: The teacher should then introduce the terms of addition, which are the numbers being added. For example, in '2 + 3 = 5', 2 and 3 are the terms of addition. The teacher can use physical objects, such as counting blocks, to demonstrate this and make the concept more tangible for students.

   1.3. Addition Result: The teacher should explain that the result of addition is called the sum. For example, in '2 + 3 = 5', 5 is the sum. The teacher should emphasize that the sum is the answer to an addition and that it is important to know how to find the sum correctly.

2. Practice Addition with One-Digit Numbers (5 - 7 minutes)

   2.1. Step-by-Step Explanation: The teacher should provide a step-by-step guide on how to perform an addition. He should start with additions of one-digit numbers to make the process simpler and more understandable for students. For example, '3 + 2 = ?'. The teacher should explain that to find the sum, they should start with the first number, which is 3, and count 2 forward. The answer is 5. The teacher should reinforce that addition is a cumulative operation and that students should add in order, starting with the first number.

   2.2. Practical Examples: The teacher should then present several practical examples of simple one-digit additions and ask students to find the sums. He should walk around the classroom and offer help and guidance as needed.

3. Introduction to Addition with Two and Three-Digit Numbers (5 - 6 minutes)

   3.1. Step-by-Step Explanation: The teacher should introduce the concept of adding numbers with two or three digits. He can use physical objects, such as counting sticks or toy coins, to make the concept more tangible. The teacher should explain that when adding numbers with two or three digits, students should start with the rightmost digit and continue, moving to the left.

   3.2. Practical Examples: The teacher should then present several practical examples of additions with two or three-digit numbers and ask students to find the sums. He should walk around the classroom and offer help and guidance as needed.

The development of the lesson should be interactive and engaging, with the teacher encouraging students to participate and solve problems on their own. The teacher should use simple and direct language, adapted to the students' level of understanding, and should be attentive to clarify any doubts that may arise.

Return (10 - 15 minutes)

1. Group Discussion (5 - 7 minutes)

   1.1. Answer Verification: The teacher should start the group discussion by asking some students to share the solutions they found for the proposed additions. He should verify if the solutions are correct and if the students applied the concepts and strategies learned during the lesson correctly.

   1.2. Explanation of the Process: After verifying the answers, the teacher should ask students to explain how they arrived at those solutions. This will help consolidate students' understanding of addition concepts. The teacher can ask students to use physical objects, such as counting blocks, to demonstrate their strategies.

2. Connection with Theory (3 - 4 minutes)

   2.1. Reflection on Strategies: The teacher should then ask students if they noticed any common strategy or pattern when solving the additions. For example, students may notice that they always start the addition with the rightmost number and then move to the left. This will allow the teacher to highlight the importance of addition strategies and how they can facilitate the resolution process.

   2.2. Review of Addition Terms: The teacher should also review the terms of addition, reminding students that they are the numbers being added, and the result of the addition, which is the sum. He can do this by asking questions like 'What are the terms of addition in 3 + 2 = 5?' and 'What is the sum of 3 + 2?'.

3. Final Reflection (2 - 3 minutes)

   3.1. Everyday Application: To conclude the lesson, the teacher should ask students to reflect on how addition is used in their daily lives. He can ask questions like 'Where do you see addition being used outside of school?' or 'How can addition help you in your daily tasks?'.

   3.2. Relevance of Addition: The teacher should emphasize that addition is an important skill that they will use in many different situations. He should encourage students to practice their addition skills at home and to look for opportunities to use addition in their daily lives.

The return should serve to consolidate students' learning, allowing them to reflect on what they have learned and how they can apply that knowledge. The teacher should use this stage to assess the effectiveness of the lesson and identify any areas that may need reinforcement or review.

Conclusion (5 - 7 minutes)

1. Lesson Summary (2 - 3 minutes)

   1.1. Content Review: The teacher should start the conclusion by giving a brief summary of the main points covered during the lesson. He should remind students about the definition of addition, which is a mathematical operation that combines two or more numbers to obtain a total. Additionally, the teacher should review the terms of addition (the numbers being added) and the result (the sum) of an addition.

   1.2. Recollection of Strategies: The teacher should then recall the addition strategies that were taught during the lesson. He can emphasize the importance of starting with the rightmost number and moving to the left when adding numbers with more than one digit.

2. Linking Theory with Practice (1 - 2 minutes)

   2.1. Reinforcement of the Importance of Addition: The teacher should explain that addition is one of the most important mathematical operations, used in many everyday situations. He can give specific examples, such as counting toys, calculating the sum of scores in a game, or dividing a quantity of candies among friends.

   2.2. Connection of Theory with Practice: The teacher should emphasize how the lesson connected the theory of addition with concrete practices. For example, he can say 'We learned that addition is a way to combine numbers. Today, we used counting blocks, apples, and balloons to help us understand and practice addition'.

3. Extra Materials (1 - 2 minutes)

   3.1. Suggestion of Additional Materials: The teacher should suggest materials for students to deepen their knowledge of addition. This may include interactive online games, math books with addition activities, or math apps for mobile devices.

   3.2. Encouragement for Practice at Home: The teacher should encourage students to practice their addition skills at home. He can suggest that students practice addition during daily activities, such as counting objects, calculating the sum of numbers on license plates, or dividing a quantity of food among family members.

4. Closure (1 minute)

   4.1. Relevance of the Subject: The teacher should end the lesson by reinforcing the relevance of addition and how it is an important skill for daily life and for mathematics. He can say 'Congratulations to everyone for learning about addition today! Addition is a very important skill that you will use in many different situations, inside and outside of school'.

   4.2. Encouragement for Participation: Finally, the teacher should encourage students to actively participate in future lessons and to continue exploring the wonder of mathematics.

The conclusion should serve to consolidate students' learning, reinforce the importance of what was taught, and encourage continuous practice. The teacher should maintain a positive and encouraging tone, and be available to answer any questions or doubts students may have.