Objectives (5 - 7 minutes)

1. Understand the concept of percentage and its application in daily life: Students should be able to understand the concept of percentage as a way to represent a part of a whole in terms of a hundred. They should also be able to identify examples of percentages in everyday situations.

2. Recognize notable percentages: Students should learn to identify and recognize the most commonly used percentages, such as 25%, 50%, and 75%. They should also understand the relationship between these percentages and the equivalent fractions 1/4, 1/2, and 3/4.

3. Solve problems involving notable percentages: Students should apply their knowledge of notable percentages to solve simple problems, such as finding 25% of a number, or adding 50% to a number.

Secondary objectives:

• Promote critical thinking and problem-solving: Students should be encouraged to think critically and solve problems creatively, applying their knowledge of notable percentages.

• Stimulate teamwork: Through group activities, students should learn to work as a team, sharing ideas and collaborating in problem-solving.

Introduction (10 - 15 minutes)

1. Review of previous content: The teacher should start the lesson by reviewing the concepts of fractions and percentages, which were covered in previous classes. A quick review can be proposed through simple questions, such as "What is a fraction?" and "What is a percentage?" Students should be encouraged to participate actively, answering questions and giving examples.

2. Problem situations: The teacher should present two problem situations that will be solved throughout the lesson. The first situation could be: "If in a class of 30 students, 25% are girls, how many girls are there in the class?" The second situation could be: "If you have 10 reais and need to buy a toy that costs 50% of that amount, how much will you spend?"

3. Contextualization: The teacher should explain to the students that percentage is an important tool in daily life. Examples of real situations where percentages are used can be given, such as a 50% discount promotion in a store, or a cake recipe that calls for 25% sugar. This helps to show students the relevance of the subject.

4. Capturing students' attention: To spark students' interest, the teacher can present two curiosities about percentages. The first one is that the word "percentage" comes from the Latin "per centum," which means "per hundred." The second curiosity is that the percentage symbol (%) was created by an Italian mathematician from the 15th century, named Luca Pacioli, who was a friend of Leonardo da Vinci.

5. Introduction of the topic: Finally, the teacher should introduce the topic of the lesson - notable percentages. Explain that there are certain percentages that are very common and it is important to know how to recognize and use them. Examples can be given, such as 25% (1/4), 50% (1/2), and 75% (3/4), and explain that these percentages represent equivalent fractions.

Development (20 - 25 minutes)

1. Activity "Building a notable pizza": Divide the class into groups of 4 to 5 students. Each group will receive a blank sheet of paper and colored pencils. The teacher will explain that they will have to draw a pizza and "divide" it according to the notable percentages that will be drawn. The percentages can be represented in the form of a fraction (for example, 1/4 for 25%, 1/2 for 50%, and 3/4 for 75%).

   • The teacher will draw a notable percentage and the group will have to draw the corresponding amount of pizza to the fraction.

   • For example, if the teacher draws 75%, the group will have to draw 3/4 of the pizza.

   • The process will be repeated until all notable percentages are drawn.

   In the end, each group will present their pizza and explain the fractions corresponding to the notable percentages drawn. This will allow students to visualize the relationship between percentages and fractions in a fun and interactive way.

2. Activity "Assembling a percentage puzzle": For this activity, the teacher will need to prepare a set of puzzles in advance. Each puzzle will consist of an image divided into parts, and each part will have a percentage written, along with the respective equivalent fraction.

   • The teacher will distribute one puzzle to each group. Students will have to assemble the puzzle, combining the parts that represent the same percentage and the equivalent fraction.

   • For example, if a piece of the puzzle says "25%" and "1/4", students will have to find the other part of the puzzle that also represents "25%" and "1/4".

   This activity will help students reinforce the idea that notable percentages have corresponding fractions and practice the correspondence between fractions and percentages.

3. Activity "Percentage race": For this activity, the teacher will need large cards with written percentages (25%, 50%, and 75%) and a set of numbered cards from 1 to 10.

   • The teacher will spread the percentage cards at one end of the room and the numbered cards at the other end.

   • The teacher will divide the class into two teams and each team will designate a "runner".

   • The teacher will say a number and a percentage (for example, "Number 3 and 50%"). The "runners" from each team will have to run to card number 3 and then to the card representing 50%.

   • The first "runner" to reach the 50% card will be the winner.

   This game, besides being fun, will help students associate numbers with the concepts of percentage and fraction in a practical and playful way.

Choose one of the activities above according to the available time and the dynamics of the class. Remember to adapt the activities according to the students' level of difficulty. The goal is to make learning fun and engaging, encouraging the active participation of everyone.

Feedback (8 - 10 minutes)

1. Group discussion (3 - 4 minutes): After the practical activities, the teacher should gather the whole class for a group discussion. Each group should share their solutions and the results found. The teacher should ask guiding questions to encourage students to explain their answers and strategies used. For example, "Why do you think this part of the pizza represents 50%?" or "How do you know that this part of the puzzle represents 25%?".

2. Connection to theory (3 - 4 minutes): Next, the teacher should review the notable percentages (25%, 50%, and 75%) and explain how they relate to the equivalent fractions (1/4, 1/2, and 3/4). The teacher can use the students' solutions to illustrate these relationships. For example, if a group correctly drew 3/4 of the pizza to represent 75%, the teacher can point out that 3/4 is the same as 75/100, that is, 75%.

3. Reflection on learning (2 - 3 minutes): Finally, the teacher should ask students to reflect on what they learned in the lesson. Two simple questions can be asked to guide this reflection:

   • "What did you find most interesting about the notable percentages and how they relate to equivalent fractions?"

   • "How can you use what you learned today in everyday situations?"

The teacher should give a minute for students to think about the answers and then some students can share their reflections with the class. This reflection step helps to consolidate learning and raise awareness among students about the practical application of what they learned.

Remember that the time for each stage may vary according to the dynamics of the class and the remaining time. It is important to ensure that all students have the opportunity to share their solutions and reflections, promoting an environment of respect and appreciation for everyone's efforts.

Conclusion (5 - 7 minutes)

1. Review of contents (2 - 3 minutes): The teacher should start the conclusion of the lesson by reviewing the main points discussed. The concepts of percentage and notable percentages (25%, 50%, and 75%), and the relationship of these percentages with equivalent fractions (1/4, 1/2, and 3/4) should be recalled. The teacher can ask students to summarize these concepts in their own words, reinforcing learning.

2. Connection between theory and practice (1 - 2 minutes): Next, the teacher should explain how the lesson connected theory with practice. It should be highlighted how the activities allowed students to visualize and manipulate notable percentages, facilitating the understanding and memorization of the concepts. Additionally, it should be emphasized how the problem situations proposed at the beginning of the lesson were solved using notable percentages.

3. Extra materials (1 minute): The teacher can suggest some extra materials for students who wish to deepen their knowledge on the subject. Books on children's mathematics that address the topic of percentages, educational websites with interactive games on percentages, or even activities to be done at home with the help of parents can be indicated. Some examples of educational websites are Khan Academy (https://www.khanacademy.org/) and Math Playground (https://www.mathplayground.com/).

4. Importance of the subject (1 - 2 minutes): Finally, the teacher should emphasize the importance of the subject for students' daily lives. It should be explained that percentages are widely used in various situations, such as discounts in stores, interest calculation in loans or investments, and even in cooking recipes. The teacher can suggest that students pay attention and try to identify percentages in everyday situations, such as in TV commercials, product labels, or news in newspapers.

5. Closure (1 minute): The teacher should end the lesson by thanking everyone for their participation, reinforcing the importance of learning mathematics, and encouraging students to continue exploring and having fun with numbers. It can end with a motivating quote, such as "Mathematics is the language with which God wrote the universe." - Galileo Galilei.