Objectives (5 minutes)

1. Main Objective: Introduce the concepts of capacity and mass as units of measurement to solve everyday problems. The student should be able to understand the relationship between these quantities and how they are applied in different situations.

2. Secondary Objective: Provide students with the opportunity to explore and manipulate different materials to develop a practical notion of capacity and mass. This can be done through playful activities and simple experiments involving the comparison of volumes and weights.

3. Secondary Objective: Foster critical thinking and problem-solving through questions that require the application of the concepts learned. Students should be able to identify the appropriate unit of measurement for a given situation and use that unit to solve the proposed problem.

Introduction (10 - 15 minutes)

1. Review of Previous Content: The teacher should start the lesson by reminding students about the length measurement units that have already been studied, such as centimeter, meter, and kilometer. This will help establish a solid foundation for the introduction of the new capacity and mass measurement units.

2. Problem-Solving Scenarios: Next, the teacher should propose two problem-solving scenarios to pique students' interest. The first one could be: 'How can we know how much water a glass can hold?' and the second: 'How can we find out the weight of an object without using a scale?'. These questions will direct students' attention to the concepts of capacity and mass.

3. Contextualization: The teacher should explain that capacity and mass are measurements widely used in our daily lives. For example, we use capacity to measure the amount of water in a bottle, and we use mass to know the weight of a package we receive. The teacher can also mention that these measurements are used in various professions, such as cooks, carpenters, and even astronauts!

4. Topic Introduction: To introduce the topic and capture students' attention, the teacher can share two curiosities: The first one is that the capacity measurement unit, the liter, is derived from the French word 'litre', which means 'a quarter'. The second curiosity is that the mass measurement unit, the gram, was originally defined as the mass of a cubic centimeter of distilled water at a certain temperature.

5. Engaging Students' Attention: Finally, the teacher should present two real-life situations that demonstrate the importance of capacity and mass measurements: The first one is the importance of measuring the amount of water we drink every day to keep our bodies hydrated. The second one is the importance of weighing an object before placing it in a structure, such as a building, to ensure safety. These situations will help students realize the relevance and practical application of what they are learning.

Development (20 - 25 minutes)

1. Theory - Capacity: The teacher should start by explaining that capacity is the amount of liquid an object can hold. The teacher should then introduce the capacity measurement units: milliliter (ml) and liter (l). To facilitate understanding, the teacher can make the following comparisons:

   • 1 glass of water is equal to 250 ml.
   • 1 bottle of soda is equal to 2 liters.
   • 1 bucket of water is equal to 10 liters.

2. Theory - Mass: Next, the teacher should explain that mass is the amount of matter an object possesses. The teacher should then introduce the mass measurement units: gram (g) and kilogram (kg). Again, to facilitate understanding, the teacher can make the following comparisons:

   • A small apple weighs about 100 grams.
   • A large watermelon weighs about 10 kilograms.
   • An adult weighs around 60 to 90 kilograms.

3. Practical Activity 1 - Measuring Capacity: The teacher should propose an activity in which students will have to measure the capacity of different containers. For this, the teacher can provide a variety of glasses, bottles, buckets, among others. Students should use a graduated syringe or a measuring cup to measure the capacity of each container and record the results. This activity will help students better understand the concept of capacity and practice using capacity measurement units.

4. Practical Activity 2 - Measuring Mass: Next, the teacher should propose an activity in which students will have to measure the mass of different objects. For this, the teacher can provide a variety of objects of different weights. Students should use a scale to measure the mass of each object and record the results. This activity will help students better understand the concept of mass and practice using mass measurement units.

5. Discussion of Activities: After completing the practical activities, the teacher should facilitate a classroom discussion where students will have the opportunity to share their findings and learn from each other. The teacher should emphasize the importance of precision in measurement and choosing the correct unit of measurement in each situation.

6. Application of Concepts - Problem-Solving Scenarios: To consolidate students' understanding of the concepts of capacity and mass, the teacher should propose two problem-solving scenarios involving the application of these measurement units. For example, 'If a soda bottle has 2 liters and I drink 1 glass of 250 ml, how many glasses of soda can I drink?' and 'If a watermelon weighs 10 kg and I bought a watermelon that weighs 3 kg, how much less does the watermelon I bought weigh compared to the watermelon that weighs 10 kg?'. These problem-solving scenarios will help students apply the concepts learned in a practical way and develop their problem-solving skills.

7. Theory-Practice Connection: At the end of the development, the teacher should revisit the theoretical concepts explained at the beginning of the lesson and make a connection with the practical activities carried out. The teacher should reinforce that practical activities are a way to apply theory in practice, and that theory is the basis for carrying out the activities. This step is important to ensure that students understand the relationship between theory and practice, and feel confident in applying the concepts learned in everyday situations.

Return (10 - 15 minutes)

1. Group Discussion: The teacher should gather all students and facilitate a group discussion about the solutions found for the proposed problem-solving scenarios. Each group should share their solution and the process used to reach it. The teacher should encourage students to ask questions and comment on their peers' solutions, creating a collaborative learning environment.

2. Connection with Theory: After the discussion, the teacher should revisit the theoretical concepts presented at the beginning of the lesson and relate them to the solutions found by the students. The teacher can ask: 'How do the capacity and mass measurement units we studied apply to the solutions you found?'. This step is important to reinforce the connection between theory and practice, and to ensure that students understand the relevance of the concepts learned.

3. Individual Reflection: Next, the teacher should suggest that students reflect individually on what they learned in the lesson. For this, the teacher can ask two simple questions:

   • 'What did you enjoy learning most about capacity and mass today?'
   • 'How can you use what you learned today in situations in your daily life?'

   Students should have a minute to think about the answers. This reflection step helps students internalize what they learned and realize the applicability of the concepts of capacity and mass in their lives.

4. Feedback: Finally, the teacher should provide feedback to students, praising their efforts and progress, and reinforcing the key points of the lesson. The teacher should also encourage students to continue practicing and exploring the concepts of capacity and mass at home. The teacher can suggest extra activities, such as measuring the capacity of different containers in the kitchen, or weighing objects on a scale, so that students can apply what they learned in a fun and practical way.

5. Closure: To conclude the lesson, the teacher should emphasize the importance of what was learned, highlighting that capacity and mass are fundamental measurements that we use every day. The teacher can also mention that with the knowledge acquired, students will be able to solve everyday problems more efficiently and accurately. Finally, the teacher should congratulate the students for their effort and participation in the lesson, and encourage them to continue exploring and learning about the wonderful world of mathematics.

Conclusion (5 - 10 minutes)

1. Lesson Summary: The teacher should start the conclusion by giving a brief summary of the main points covered in the lesson. This includes the introduction of capacity (milliliter and liter) and mass (gram and kilogram) measurement units, the contextualization of these measurements in everyday life, the practice of measuring capacity and mass through playful activities, and the application of the learned concepts in problem-solving scenarios.

2. Connection between Theory, Practice, and Applications: Next, the teacher should emphasize the importance of the connection between theory, practice, and applications. It should be emphasized that theory provides the basis for practice, which in turn allows the application of the learned concepts in real situations. The teacher can review the practical activities carried out and show how they helped solidify students' understanding of the concepts of capacity and mass.

3. Extra Materials: The teacher should then suggest some extra materials to complement students' learning. This may include educational websites that offer interactive games and measurement activities, textbooks that explore the topic of measurement in a playful way, and educational videos that demonstrate practical experiments related to the theme. The teacher should encourage students to explore these materials at home and to share their discoveries and learnings in the next lesson.

4. Relevance of the Subject: Finally, the teacher should emphasize the relevance of the subject covered for students' daily lives. It should be explained that capacity and mass are measurements that we constantly use in our lives, whether when preparing a cake recipe, filling a bucket with water, or weighing a package at the post office. In addition, the teacher should mention that understanding these measurements and the ability to use them effectively can facilitate problem-solving in everyday life and contribute to greater autonomy and confidence for students.

5. Closure: To conclude the lesson, the teacher should congratulate the students on their learning and effort, and reinforce the importance of staying curious and motivated in the pursuit of knowledge. The teacher should remind students that mathematics is a fun and challenging discipline, and that each lesson is an opportunity to discover something new and exciting. Finally, the teacher should invite students to reflect on what they learned in the lesson and to apply this knowledge in their daily lives.