Objectives (5 minutes)

1. Understand the concept of composition of natural numbers less than 10,000, that is, the ability to build a number from its component parts.
2. Understand the concept of decomposition of natural numbers less than 10,000, that is, the ability to separate a number into its component parts.
3. Apply the concepts of composition and decomposition in solving mathematical problems involving natural numbers less than 10,000.

Secondary Objectives:

1. Develop teamwork and collaboration skills during the proposed activities.
2. Stimulate creativity and problem-solving in a playful and fun way, through games and practical activities.

Introduction (10 - 15 minutes)

1. Concept Review: The teacher starts the lesson by reviewing the concepts of natural numbers and the number sequence up to 10,000. He may ask students to give examples of natural numbers less than 10,000, such as 2345, 6789, etc. (5 minutes)

2. Problem Situations: The teacher presents two problem situations that will be the starting point for the lesson discussion:

   • Student A has 4523 candies and wants to divide them equally among his 3 friends. How many candies will each friend receive?
   • Student B has 1200 reais and wants to buy 3 toys that cost 250 reais each. Does he have enough money to buy all the toys? (5 minutes)

3. Contextualization: The teacher explains that the composition and decomposition of numbers is a very important skill in mathematics, as it helps us better understand the structure of numbers and solve more complex problems. He can give examples of how we use composition and decomposition in everyday life, such as when we go to the market and need to add up the value of several products, or when we receive change and need to divide the amount into bills and coins. (5 minutes)

4. Topic Introduction: To spark students' interest, the teacher can start by sharing a curiosity:

   • 'Did you know that the ancient Egyptians already used the composition and decomposition of numbers? They used a numbering system called 'base 10 system', which is the same as we use today. They also used a fraction system that was based on the decomposition of numbers. Amazing, isn't it?' (3 minutes)

5. Learning Preparation: The teacher explains that students will learn more about the composition and decomposition of numbers through practical and fun activities. He emphasizes that all students are capable of learning and that with practice and effort they will become true masters in the art of mathematics. (2 minutes)

Development (20 - 25 minutes)

1. Activity: 'Building and Breaking Giant Numbers' (10 - 12 minutes)

   • The teacher divides the class into groups of 4 or 5 students and gives each group a set of cards numbered from 1 to 9.
   • Each group is given a task to build a number up to 10,000 using the cards. For example, the teacher may ask the group to build the largest or smallest possible number, or a number that ends with a specific digit.
   • Once all groups have built their numbers, they must explain to the class how they decided where to place each card and why. This helps reinforce the idea that a number is the sum of its parts, and that the order of the parts matters.
   • After the discussion, the teacher may suggest that each group turn the number built in the first part of the game into a sequence of math problems. For example, if the number built was 5,874, the group can create problems like: 'How many thousands does this number have?' or 'What is the value of the ten-thousands digit?'.

2. Activity: 'Number Treasure Hunt' (10 - 12 minutes)

   • Before the lesson, the teacher hides a series of cards numbered with numbers less than 10,000 in the classroom (or in an external area of the school, if possible). The cards should have numbers that are multiples of 10 or have some particular property to make them easier to work with.
   • Students will be divided into groups and given a magnifying glass and a sheet with numbers to search for. Each number they find, they must write down on the sheet.
   • After the search, each group must decompose the numbers found, that is, separate them into units, tens, hundreds, and thousands. Students must demonstrate their understanding of the concept by explaining how they performed this decomposition.
   • To conclude, the teacher can choose a number, and the groups must add the parts of that number, demonstrating the ability to compose a number from its parts.

Both activities are playful, collaborative, and encourage teamwork, as well as promote the understanding of the concepts of composition and decomposition of natural numbers less than 10,000. The teacher can choose one of the activities to carry out in the classroom, or adapt them according to the available time and the dynamics of the class.

Return (10 - 15 minutes)

1. Group Discussion (5 - 7 minutes)

   • The teacher gathers all students in a large circle to share the solutions and strategies found by each group during the activities.
   • Each group will have the opportunity to present the numbers they built or found, and explain how they performed the decomposition or composition of them.
   • During the presentations, the teacher should encourage students to ask questions and make comments, stimulating dialogue and reflection on the processes of composition and decomposition.

2. Connection to Theory (3 - 5 minutes)

   • After the presentations, the teacher revisits the theoretical concepts of composition and decomposition of numbers, reinforcing the ideas discussed during the practical activities.
   • He can ask questions like: 'Did you notice how important it is to understand the structure of a number to be able to compose and decompose?' or 'How can the decomposition of a number help us solve math problems?'.

3. Final Reflection (2 - 3 minutes)

   • To conclude the lesson, the teacher proposes that students reflect on what they have learned. He asks two simple questions and requests that students think silently for a minute before answering.
   • The questions can be:
     1. 'What was the most fun part of today's lesson and why?'
     2. 'How could you use what you learned today in everyday situations?'
   • After the reflection time, the teacher invites students to share their answers, reinforcing the idea that mathematics is not just a school subject, but something that has practical application and can be interesting and fun.

This moment of return is essential to consolidate students' learning, allowing them to reflect on what they have learned and how they can apply that knowledge. In addition, the group discussion and connection to theory allow the teacher to assess students' understanding and identify possible difficulties or learning gaps that need to be addressed in future lessons.

Conclusion (5 - 10 minutes)

1. Summary of Contents (2 - 3 minutes)

   • The teacher starts the conclusion by reiterating the main points covered during the lesson. He summarizes the concepts of composition and decomposition of natural numbers less than 10,000 and the importance of these concepts in solving mathematical problems.
   • He can give practical examples of how students applied these concepts in the activities carried out, reinforcing the idea that mathematics is not something abstract and distant, but something we use in our daily lives.

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

   • The teacher explains how the lesson connected mathematical theory with practice. He emphasizes that the composition and decomposition of numbers are not just abstract concepts, but tools that students can use to solve real problems.
   • He also highlights that the lesson used a practical and playful approach, through games and group activities, to make learning more interesting and meaningful.

3. Extra Materials (1 - 2 minutes)

   • The teacher suggests extra materials for students who wish to deepen their knowledge on the subject. He can recommend books, websites, online games, and educational videos that address the composition and decomposition of numbers in a fun and interactive way.
   • He can also suggest that students practice the composition and decomposition of numbers at home, for example, by asking them to solve everyday math problems, such as calculating the total value of a purchase at the supermarket or making an equal division of a snack among siblings.

4. Importance of the Subject (1 - 2 minutes)

   • In conclusion, the teacher emphasizes the importance of the subject for students' daily lives. He explains that the composition and decomposition of numbers are fundamental skills for the study of mathematics, as they help us better understand the structure of numbers and perform mathematical operations more efficiently.
   • Furthermore, he points out that these skills are useful in various everyday situations, from solving math problems to performing simple tasks like counting money or measuring ingredients for a recipe.

The conclusion is an important moment to reinforce students' learning, helping them to consolidate the concepts learned and understand the relevance of these concepts to their daily lives. In addition, by suggesting extra materials and activities for home, the teacher encourages autonomous study and deepening of students' knowledge.