Objectives (5 minutes)

1. Main Goal: Introduce the concept of converting length measurement units (meter, centimeter, and millimeter) to students in grades 3-5. Students should be able to understand that measurement units express the size of an object and can be converted from one to another.

2. Secondary Goal: Develop problem-solving skills by identifying, comparing, and converting different units of length measurement. Students should be able to apply the knowledge acquired to solve practical problems related to the conversion of measurement units.

Secondary objectives:

• Familiarize students with length measurement units: meter, centimeter, and millimeter.

• Develop problem-solving skills by identifying, comparing, and converting different length measurement units.

• Apply the knowledge acquired to solve practical problems related to unit conversion.

Introduction (10-15 minutes)

1. Content Review: The teacher begins the lesson by reminding students of the length measurement units they have already studied: meter, centimeter, and millimeter. They can ask students to identify objects in the classroom or at home that have different length measurement units. For example, a ruler can be measured in centimeters and millimeters, while a table can be measured in meters.

2. Problem Situations: The teacher presents two problem situations to motivate students to understand the need to convert length measurement units. The situations can be:

   • If a student wants to measure the length of their table and only has a ruler that measures in centimeters, how can they find out how many meters the table is?
   • If a student has a 2-meter string and wants to divide it equally among 4 friends, how can they find out the number of centimeters each friend will receive?

3. Contextualization: The teacher contextualizes the importance of converting length measurement units in the students' daily lives. They can mention real-life situations, such as going to the supermarket and buying fruits and vegetables, which are sold by the kilo or by the unit, and the need to know how to convert units to make the correct purchase.

4. Topic Introduction: The teacher introduces the lesson topic, explaining that they will learn how to convert length measurement units. They can pique students' curiosity by explaining that converting measurement units is a very important skill that is used by many people in different professions, such as architects, builders, cooks, seamstresses, and others.

Development (20-25 minutes)

1. Theory on Converting Length Measurement Units (10-12 minutes)

   • The teacher will explain in a clear and simple way what the conversion of length measurement units is. They can use practical examples, such as converting the size of an ant in meters, centimeters, and millimeters, to make the concept more tangible for the students.

   • The teacher should address the relationship between the length measurement units, explaining that 1 meter is equal to 100 centimeters and 1 centimeter is equal to 10 millimeters. They can do this by using a large, colorful ruler so that all students can see and understand the relationship between the units.

   • The teacher should explain that to convert one length measurement unit to another, simply multiply or divide by the equivalence number. For example, if we want to convert 1 meter to centimeters, just multiply by 100. If we want to convert 50 centimeters to millimeters, just multiply by 10.

2. Practical Activities for Converting Length Measurement Units (10-13 minutes)

   • The teacher can have students bring objects from home or school to class that have different length measurement units. Students should then measure these objects and then convert the unit of measure. For example, if a student measures a pen and finds 15 centimeters, they can convert that measurement to millimeters by multiplying by 10, getting 150 millimeters.

   • The teacher can bring different objects into the classroom and ask students to convert their length measurements from one unit to another. For example, the teacher can measure the height of a table in meters and ask students to convert that measurement to centimeters or millimeters.

   • The teacher should circulate around the room during the activities, assisting students who are having difficulty and offering extra challenges to students who are more advanced.

3. Length Measurement Unit Conversion Game (5-10 minutes)

   • To make learning more playful and fun, the teacher can suggest a unit measurement conversion game. They can divide the class into two groups and give each group a set of cards with length measurements in different units. Students must then convert the measurements from one unit to another as quickly as possible. The group that converts correctly and the fastest wins a point.

   • The teacher should supervise the game, ensuring that all students are participating and understanding the activity. They can then do a group review, discussing the correct answers and the strategies used by the groups.

Feedback (10-15 minutes)

1. Group Discussion (5-7 minutes):

   • After the practical activities, the teacher brings all the students together in a large circle for a group discussion. They ask some students to share the solutions or strategies they used to convert the length measurement units.
   • The teacher should ask questions to ensure that all students understand the concepts presented. For example, they could ask: "Why do we multiply by 100 to convert meters to centimeters?" or "Why do we divide by 10 to convert centimeters to millimeters?".
   • The teacher should praise the students' efforts and contributions, encouraging them to continue learning and exploring the concepts presented.

2. Connecting Theory with Practice (3-5 minutes):

   • The teacher then asks the students to reflect on how the theory presented in class connects with the practical activities they did. They could ask: "How can the conversion of length measurement units that we learned today help us in our daily lives?".
   • They can also ask students to think about new situations in which they can apply what they have learned. For example, "If you were going to buy a pencil that costs R$0.50 per centimeter, how could you convert the price to centimeters?".

3. Lesson Review (2-3 minutes):

   • To end the lesson, the teacher does a quick review of the main points covered. They reinforce that the length measurement units (meter, centimeter, and millimeter) are used to express the size of objects and that it is possible to convert from one unit to another by multiplying or dividing by the equivalence number.

   • They can also remind students that to convert a larger unit to a smaller unit, we must multiply, and to convert a smaller unit to a larger unit, we must divide.

   • The teacher can suggest extra materials for students who want to deepen their learning, such as online games, interactive apps, textbooks, and others.

Conclusion (5-7 minutes)

1. Summary and Recapitulation:

   • The teacher begins the conclusion of the lesson by summarizing the main points covered. They recap that the students learned about the conversion of length measurement units (meter, centimeter, and millimeter) and how to apply this knowledge to solving problems.
   • They also reinforce that to convert from one unit of measurement to another, simply multiply or divide by the equivalence number.

2. Connection between Theory, Practice, and Applications:

   • The teacher highlights how the lesson connected theory, practice, and applications. They mention that the theory was presented in a clear and simple way, with practical examples that the students could measure and convert in the classroom.
   • They also emphasize how the practical activities and the game allowed students to apply the knowledge they acquired in a fun and challenging way.

3. Extra Materials:

   • The teacher suggests some extra materials for students who want to deepen their learning. They can indicate textbooks, online games, interactive apps, and educational websites that address the topic of converting length measurement units.
   • They can also suggest that students practice converting units of measurement in their daily lives, observing and measuring the objects around them.

4. Importance of the Subject:

   • Finally, the teacher concludes the lesson by reinforcing the importance of the topic covered. They explain that converting length measurement units is a fundamental skill that is used in many everyday situations, such as buying food, building objects, sewing, cooking, and others.
   • They encourage students to continue exploring and applying what they have learned, remembering that practice makes perfect.