Lesson Plan | Traditional Methodology | Addition and Subtraction of Naturals Less than 1,000

Objectives

Duration: 10 to 15 minutes

The purpose of this stage is to ensure that students clearly understand the objectives of the lesson, preparing them for the content to be taught. By defining the objectives, the teacher establishes clear and measurable expectations, facilitating learning and assessment of student progress.

Main Objectives

1. Teach students to add numbers up to 3 digits using algorithms.

2. Teach students to subtract numbers up to 3 digits using algorithms.

3. Enable students to solve problems involving the addition and subtraction of numbers up to 3 digits.

Introduction

Duration: 10 to 15 minutes

The purpose of this stage is to capture the students' attention and contextualize the importance of learning addition and subtraction of natural numbers. By connecting the topic to the students' daily lives and presenting a historical curiosity, the teacher makes the lesson more interesting and relevant, facilitating students' understanding and engagement.

Context

 To start the lesson, begin by explaining to the students that math is present in our daily lives in various ways. Say that, even if we don't always realize it, we are constantly adding and subtracting numbers. For example, when we go to the market and buy fruits, we need to add the prices to know how much we will pay. Similarly, when we want to know how much money we still have after spending, we need to subtract the spent amount from the total we had.

Curiosities

易 Let's share an interesting fact: Did you know that the ancient Egyptians already used methods of addition and subtraction thousands of years ago? They used symbols and drawings to represent numbers and solve mathematical problems. Today, we use numbers and algorithms that help us perform these operations more quickly and efficiently!

Development

Duration: 50 to 60 minutes

The purpose of this stage is to provide students with a practical and detailed understanding of the operations of addition and subtraction of natural numbers up to 3 digits. By explaining the concepts and providing detailed examples, the teacher helps students develop the skill to perform these operations accurately. Solving practical problems allows students to apply what they have learned in everyday situations, reinforcing the importance and utility of mathematical operations.

Covered Topics

1. Addition of Natural Numbers up to 3 Digits: Explain that addition is the mathematical operation that combines two numbers to form a third number, called the sum. Show how to align the numbers vertically and add digit by digit, starting from the right. Use simple examples and gradually increase the difficulty. 2. Subtraction of Natural Numbers up to 3 Digits: Detail that subtraction is the mathematical operation that determines the difference between two numbers. Show how to align the numbers vertically and subtract digit by digit, starting from the right. Explain the concept of 'borrowing' when the subtracted digit is greater than the minuend. 3. Solving Problems Involving Addition and Subtraction: Present practical problems that require the operations of addition and subtraction. Explain step by step how to identify the necessary operation to solve each problem and how to organize the data to find the correct solution.

Classroom Questions

1. What is the sum of 245 and 378? 2. Subtract 123 from 489. 3. If João has 256 marbles and wins 134 more, how many marbles does he have now?

Questions Discussion

Duration: 20 to 25 minutes

The purpose of this stage is to review and consolidate students' learning, ensuring they fully understand the operations of addition and subtraction of numbers up to 3 digits. By discussing solutions and engaging students with reflective questions, the teacher reinforces the acquired knowledge and clarifies any doubts, promoting a deeper and more lasting understanding of the content.

Discussion

•  Explain the sum of 245 and 378: To add 245 and 378, align the numbers vertically and add column by column, starting from the right:

  245 +378

623

First, we add the units: 5 + 8 = 13. We place 3 in the units column and carry over 1 to the tens column. Then, we add the tens: 4 + 7 = 11, plus 1 (carried) = 12. We place 2 in the tens column and carry over 1 to the hundreds column. Finally, we add the hundreds: 2 + 3 = 5, plus 1 (carried) = 6. The final result is 623.

•  Explain the subtraction of 123 from 489: To subtract 123 from 489, align the numbers vertically and subtract column by column, starting from the right:

  489 -123

366

First, we subtract the units: 9 - 3 = 6. Then, we subtract the tens: 8 - 2 = 6. Finally, we subtract the hundreds: 4 - 1 = 3. The final result is 366.

•  Explain João's problem with marbles: João has 256 marbles and wins 134 more. To find the total, we add 256 and 134:

  256 +134

390

First, we add the units: 6 + 4 = 10. We place 0 in the units column and carry over 1 to the tens column. Then, we add the tens: 5 + 3 = 8, plus 1 (carried) = 9. Finally, we add the hundreds: 2 + 1 = 3. The final result is 390. João now has 390 marbles.

Student Engagement

1. ❓ Question: Did anyone find a different result? Why do you think that happened? 2. ❓ Reflection: How can we be sure that our calculations are correct? 3. ❓ Question: In what other everyday situations can we use addition and subtraction? 4. ❓ Reflection: What did we learn today that can help us with math problems in the future?

Conclusion

Duration: 10 to 15 minutes

The purpose of this stage is to review and consolidate the main points covered during the lesson, ensuring that students have a clear and complete understanding of the content. By connecting theory with practice and highlighting the relevance of the subject, the teacher reinforces the importance of learning and prepares students to apply the concepts in real situations.

Summary

• Detailed explanation of the addition of natural numbers up to 3 digits, including practical examples.
• Detailed explanation of the subtraction of natural numbers up to 3 digits, including the concept of 'borrowing.'
• Guided resolution of practical problems involving the addition and subtraction of natural numbers up to 3 digits.

The lesson connected theory with practice by explaining how to perform addition and subtraction operations with natural numbers up to 3 digits and then applying that knowledge to practical everyday problems. Concrete examples, such as adding prices at the market or calculating how many marbles João has, helped students visualize the usefulness of mathematical operations in real life.

Learning to add and subtract numbers is fundamental to students' daily lives. These operations are used in various daily situations, such as shopping, managing expenses and savings, and solving simple and complex problems. Additionally, being able to perform these operations accurately is a crucial skill for students' academic and personal development.