Lesson plan of Financial Mathematics: Simple Interest

Objectives (5 - 10 minutes)

1. Understanding the concept of simple interest: Students should be able to understand what simple interest is and how it is calculated. They should also be able to differentiate between simple and compound interest.
2. Solving practical problems involving simple interest: Students should be able to apply the concepts of simple interest to solve practical everyday problems, such as calculating the value of interest, the amount and the principal in a specific situation.
3. Applying the acquired knowledge to real situations: Students should be able to apply the acquired knowledge about simple interest in real situations, such as loans, financing, financial applications, installment purchases, etc.

Secondary objectives:

• Stimulate critical and analytical thinking: Students should be encouraged to think critically about stated situations and to analyze the results obtained.
• Promote collaboration and communication: Students should be encouraged to work in groups, discuss solutions and present their results to the class.

Introduction (10 - 15 minutes)

1. Review of previous content: The teacher begins the lesson by reviewing the concepts of percentage and ratio, which are essential for understanding simple interest. They can do this through a brief theoretical review or through practical problems involving these concepts. For example, you can ask students what it means to say that something has increased by 10% and how they would calculate it. (3-5 minutes)
2. Problem situations: The teacher then presents two problem situations that involve simple interest. In the first, the teacher can talk about a loan that a friend made at the bank and that needs to be repaid in monthly installments. The teacher can ask the students how they would calculate the amount of interest and the total amount to be paid. In the second situation, the teacher can talk about an investment that a person made in a fixed income fund that pays simple interest and ask the students how they would calculate the redemption value after a certain period of time. (5-7 minutes)
3. Contextualization of the importance of the subject: The teacher then contextualizes the importance of the subject by explaining that knowledge of simple interest is essential for dealing with everyday financial situations, such as loans, financing, financial applications, installment purchases, etc. The teacher can provide concrete examples of how knowledge of simple interest can help you make more informed financial decisions. For example, the teacher could talk about how calculating the amount of interest on a loan can help you choose the cheapest loan. (2-3 minutes)
4. Introduction of the topic and attention gain: Finally, the teacher introduces the topic of simple interest, explaining that it is one of the main concepts of financial mathematics. To gain students' attention, the teacher can tell the story of how interest arose in ancient times and how it has been used throughout history to create wealth. The teacher can also talk about how interest affects the modern economy and people's lives. (2-3 minutes)

Development (20-25 minutes)

1. Activity "The Learning Bank" (10-15 minutes)

• Creation of the Learning Bank: The teacher divides the class into groups of 4 or 5 students. Each group is designated as a "bank" and receives a certain amount of "learning money" (paper notes, for example). Each note represents a pre-established amount of simple interest. The teacher distributes different denominations to each group (for example, a R$100.00 note, a R$200.00 note, a R$500.00 note, etc.), ensuring that the sum of all the notes for each group is the same.
• Interest calculation: The teacher then presents the groups with a series of problem situations that involve the calculation of simple interest. Each time a group correctly solves a problem situation, they earn a new learning money note (representing the interest they earned). On the other hand, if the group cannot correctly solve the problem situation, they lose a learning money note.
• Healthy competition: The teacher can transform the activity into a healthy competition, rewarding the group with the most learning money at the end of the activity.
• Final reflection: After the activity, the teacher leads a discussion with the class, asking about the strategies used by the groups to solve the problem situations and the difficulties encountered. The objective is to have students reflect on the problem-solving process and how they can apply what they have learned in real situations.

2. Activity "The Smart Merchant" (10-15 minutes)

• Creation of the Smart Merchant: The teacher continues with the group dynamics, but this time the students become "smart merchants". Each group receives a "store" (a piece of paper with various products and their respective prices) and a "financial calculator" (a simple interest calculator model made of cardboard and paper).
• Installment sales simulation: The teacher then simulates a situation in which a customer wants to buy a product on credit. The group must calculate the amount of interest and the total value of the purchase using the financial calculator. The objective is for students to realize how interest can affect the final value of the purchase.
• Investment simulation: The teacher then simulates a situation where the "smart merchant" wants to invest the money he earned from sales. Again, the students must calculate the amount of interest and the final amount using the financial calculator.
• Final reflection: At the end of the activity, the teacher leads a discussion with the class asking about the difficulties encountered and what they learned from the activity.

3. Activity "The Simple Interest Challenge" (5-10 minutes)

• Contextualization of the activity: The teacher contextualizes the activity, explaining that simple interest is widely used in the real world, mainly in short-term financial transactions. The teacher can provide concrete examples of how simple interest is used in everyday situations, such as loans, financing, financial applications, installment purchases, etc.
• Simple Interest Challenge: The teacher then presents students with the "Simple Interest Challenge", which consists of a series of problems involving simple interest. Students should work in their groups to solve the problems. The teacher circulates around the room, assisting groups that are having difficulty.
• Presentation of results: After the time allotted for the activity, each group should present the solution to one of the problems to the class. This promotes collaboration and communication among students.
• Final reflection: The teacher concludes the activity by leading a reflection with the class on what they learned from the "Simple Interest Challenge".

Feedback (10 - 15 minutes)

1. Group discussion (5-7 minutes)

• The teacher gathers all the students together and starts a group discussion. Ask each group to share the solutions or conclusions they found during the activities. Each group has a maximum of 3 minutes to present.
• During the presentations, the teacher should encourage students to explain the steps they took to arrive at their solutions, highlighting the use of simple interest calculations. The teacher should also encourage other students to ask questions and make comments, thus promoting interaction and exchange of ideas among students.

2. Connection with theory (3-5 minutes)

• After all presentations, the teacher should summarize the main ideas and concepts discussed, relating them to the theory presented at the beginning of the lesson. For example, the teacher can highlight how students applied the concepts of simple interest to solve the problems proposed in the activities.
• The teacher can also identify possible errors or misunderstandings that arose during the discussions and clarify them, reinforcing the students' understanding of the subject matter.

3. Individual reflection (2-3 minutes)

• The teacher asks the students to reflect individually on what they have learned in class. The teacher asks questions such as: "What was the most important concept you learned today? and "What questions have not yet been answered?"
• Students have one minute to think and organize their responses. Then the teacher asks some volunteers to share their reflections with the class. This not only helps the teacher to assess what the students have learned, but also allows the students to realize what they have learned and what they still need to learn.

4. Feedback and clarification of doubts (2-3 minutes)

• Finally, the teacher asks the students to express any doubts or difficulties they still have with the topic. The teacher ensures that all questions are answered and that all misunderstandings are clarified.
• The teacher also takes this opportunity to give feedback to students on their performance during the lesson and to praise their effort and participation. This helps to motivate students and strengthens the connection between the teacher and the class.

Conclusion (5 - 10 minutes)

1. Summary and recapitulation (2-3 minutes)

• The teacher reviews the main points covered during the lesson, recapitulating the concept of simple interest, the difference between simple and compound interest, and how to calculate the amount of interest, the amount and the principal in a situation of simple interest.
• The teacher also recalls the practical skills developed, such as the ability to solve problems involving simple interest and the application of acquired knowledge to real situations.

2. Connection between theory, practice and applications (1-2 minutes)

• The teacher reinforces how the lesson connected the theory of simple interest with practice, through the activities "The Learning Bank", "The Smart Merchant" and "The Simple Interest Challenge". The teacher highlights how the students were able to experience the application of the learned concepts in practice and how this will help them to deal with real financial situations in the future.

3. Extra materials (1-2 minutes)

• The teacher suggests some complementary study materials for students who wish to further their knowledge of simple interest. The teacher can recommend books, websites, videos or applications that deal with the subject matter in a clear and didactic way.
• The teacher can also encourage students to practice more by solving extra exercises on the subject, both those that the teacher can make available and those that can be found in textbooks or on the Internet.

4. Importance of the subject in everyday life (1-2 minutes)

• Finally, the teacher reinforces the importance of simple interest in everyday life. The teacher highlights how knowledge of simple interest is essential for making informed financial decisions, such as when choosing a loan, making an investment or buying something on credit.
• The teacher can provide concrete examples of how simple interest affects people's lives, such as explaining how the value of loan installments is calculated, or by showing how interest on a financial application can make money grow more.