Lesson Plan | Traditional Methodology | Addition and Subtraction: Missing Values

Objectives

Duration: 10 - 15 minutes

The purpose of this stage of the lesson plan is to establish clear and specific objectives that students should achieve by the end of the lesson. This includes the ability to identify and calculate the missing value in subtraction and division operations, a fundamental skill for the development of mathematical thinking and problem-solving.

Main Objectives

1. Recognize the components of a subtraction (minuend, subtrahend, and difference) and identify the missing value.

2. Recognize the components of a division (dividend, divisor, quotient, and remainder) and identify the missing value.

3. Correctly calculate the missing element in subtraction and division operations.

Introduction

Duration: 10 - 15 minutes

 Purpose: The purpose of this stage of the lesson plan is to capture the students' attention and prepare them for the content to be explored. By connecting the lesson theme with everyday situations and curiosities, students perceive the relevance of learning and become more engaged. Additionally, this introduction provides a clear and motivating context for understanding the content of subtraction and division with missing values.

Context

 Context: Start the lesson by asking the students if they have ever tried solving a puzzle or a mystery game. Explain that, just like in a puzzle where missing pieces are essential to complete the image, in mathematics, sometimes we need to find a missing value to complete an operation. Today, we will learn to identify and calculate these missing values in subtraction and division operations. This skill helps us solve everyday problems, such as calculating how much money is needed to buy something or equally dividing a number of candies among friends.

Curiosities

 Curiosity: Did you know that mathematics is present in many professions? For instance, engineers need to calculate missing values to ensure that a bridge is safe, and doctors use division to determine the correct dosage of a medication based on a person's weight. The ability to find missing values is fundamental in various fields of knowledge and practical life.

Development

Duration: 40 - 50 minutes

 Purpose: The purpose of this stage of the lesson plan is to provide students with a detailed and practical understanding of the components and the process of identifying missing values in subtraction and division operations. Through clear explanations, guided examples, and classroom practice, students will develop essential skills to solve mathematical problems with confidence.

Covered Topics

1.  Components of Subtraction: Explain the components of subtraction, including the minuend (the number from which we subtract), the subtrahend (the number that is subtracted), and the difference (the result of the subtraction). Use simple examples to illustrate each component. 2.  Identifying Missing Values in Subtraction: Detail how to identify a missing value in subtraction. Present an example where the minuend is unknown (ex: ? - 3 = 5) and show how to solve this type of problem, emphasizing the importance of reversing the operation. 3.  Components of Division: Explain the components of division, including the dividend (the number being divided), the divisor (the number by which the dividend is divided), the quotient (the result of the division), and the remainder (what is left after the division). Use clear and accessible examples. 4.  Identifying Missing Values in Division: Detail how to identify a missing value in division. Present an example where the dividend is unknown (ex: ? ÷ 4 = 3) and show how to solve this type of problem, emphasizing the relationship between multiplication and division to find the missing value. 5.  Guided Problem Solving: Propose some problems to solve together with the students, guiding them step by step. Start with simpler problems and gradually increase the complexity, ensuring that all students keep up with the reasoning.

Classroom Questions

1. 1️⃣ Question 1: What is the missing value in the following subtraction problem: 12 - ? = 7? 2. 2️⃣ Question 2: Find the missing value in the following division: ? ÷ 5 = 4 3. 3️⃣ Question 3: If the dividend is 36 and the quotient is 6, what is the divisor?

Questions Discussion

Duration: 20 - 25 minutes

 Purpose: The purpose of this stage of the lesson plan is to provide a detailed review of the questions addressed, ensuring that students fully understand the methods used to find missing values in subtractions and divisions. By discussing the answers and engaging students with reflective questions, we consolidate learning and encourage critical thinking, preparing them to apply these skills in different contexts.

Discussion

•  Discussion of the Questions:

• 1️⃣ Question 1: What is the missing value in the following subtraction problem: 12 - ? = 7?

• Answer: To find the missing value, we need to reverse the operation. If 12 - ? = 7, then 12 - 7 = ?. Therefore, the missing value is 5. Explain to the students that by subtracting 7 from 12, we get the missing difference, which is 5.

• 2️⃣ Question 2: Find the missing value in the following division: ? ÷ 5 = 4

• Answer: To find the missing value, we can reverse the operation to multiplication. If ? ÷ 5 = 4, then 4 × 5 = ?. Therefore, the missing value is 20. Explain to the students that by multiplying 4 by 5, we find the missing dividend.

• 3️⃣ Question 3: If the dividend is 36 and the quotient is 6, what is the divisor?

• Answer: To find the divisor, we can use the relationship between division and multiplication. If 36 ÷ ? = 6, then 36 = 6 × ?. Therefore, the divisor is 6. Explain that by dividing 36 by the quotient 6, we obtain the missing divisor.

Student Engagement

1. ‍♂️ Student Engagement: 2. 1. Reflective Question: Why is it important to know how to reverse mathematical operations (subtraction to addition and division to multiplication) to find missing values? 3. 2. Practical Situation: If you have 15 candies and want to divide them equally among your 3 friends, how can you use division to find out how many candies each one will get? 4. 3. Challenge: Imagine you have a total of 24 pencils and want to arrange them in groups of 4 pencils each. How many groups will you have? How can you check if your answer is correct?

Conclusion

Duration: 10 - 15 minutes

 Purpose: The purpose of this stage of the lesson plan is to review and consolidate student learning, ensuring that everyone has grasped the main concepts covered. By summarizing the content, explaining the connection to practice, and highlighting the relevance of the topic, we reinforce the importance of learning and prepare students to apply these skills in various situations.

Summary

•  Components of Subtraction: Minuend, subtrahend, and difference.
•  Identifying Missing Values in Subtraction: Reversing the operation to find the missing value.
•  Components of Division: Dividend, divisor, quotient, and remainder.
•  Identifying Missing Values in Division: Relationship between multiplication and division to find the missing value.
•  Guided Problem Solving: Practical examples and joint problem-solving.

Throughout the lesson, we connected theory with practice through clear and accessible examples for the students. We demonstrated how to identify and calculate missing values in subtraction and division operations, using everyday problems and practical situations that facilitate the understanding of the relevance and application of the learned mathematical concepts.

Understanding how to identify missing values in mathematical operations is an essential skill not only for school mathematics but also for everyday life. From calculating change in purchases to equally distributing items among friends, this skill is fundamental in various situations. Furthermore, professions such as engineering and medicine often use these concepts to ensure accuracy and safety in their activities.