Lesson plan of Addition and Subtraction of Naturals Less than 1,000

Objectives (5 minutes)

1. Develop an understanding of addition and subtraction of natural numbers less than 1,000: The main goal of this lesson is for students to be able to add and subtract natural numbers less than 1,000 accurately and efficiently. They should understand the concept behind these operations and be able to apply them in different problem-solving situations.

2. Use counting, regrouping, and decomposition strategies: Students should be able to use appropriate strategies to solve addition and subtraction problems, such as counting, regrouping, and decomposing numbers. They should understand when and how to apply each of these strategies.

3. Apply mathematical knowledge to real-life situations: The ultimate goal is for students to be able to apply the knowledge they have gained in real-world situations. This includes solving problems, interpreting mathematical situations, and communicating their solutions clearly and coherently.

Introduction (10-15 minutes)

1. Review of previous content: The teacher should begin the lesson by reviewing the basic concepts of addition and subtraction that were taught in the previous year. This can be done through a quick oral review, using simple and familiar examples for the students. For instance, the teacher can ask, "If I have two apples and I get three more, how many apples will I have in total? And if I eat one apple, how many apples will I have left?"

2. Problem situations: The teacher should then present two problem situations that will be solved during the lesson. The first situation could be: "Mary has 725 stickers and receives 123 more as a gift. How many stickers will Mary have in total?". The second situation could be: "John has 845 reais and spends 432 reais on a toy. How much money will John have after buying the toy?"

3. Contextualization: The teacher should explain to the students that mathematics is very important in our daily lives, being used in various situations, such as shopping, playing games, organizing tasks, among others. For example, the teacher can mention that addition and subtraction are widely used in supermarkets, when we need to add the value of the products we want to buy, and then subtract the value of the money we have to know if we can afford it.

4. Introduction to the topic: The teacher should then introduce the topic of the lesson, explaining that they will learn how to do addition and subtraction with larger numbers, up to 1,000. For example, the teacher can say: "Today, we will learn how to add and subtract larger numbers, such as 725 and 845. This will help us solve more complex problems, such as organizing a party or planning a trip, for example."

5. Curiosity: To spark students' interest, the teacher can share the curiosity that the first symbols used to represent numbers and make calculations were created by the ancient Egyptians over 5,000 years ago. At that time, they used drawings of animals, plants, and objects to represent numbers. For example, they used a drawing of a dog to represent the number 1, a drawing of a man to represent the number 10, and so on. The idea of using symbols to represent numbers and make calculations spread throughout the world, and today we use the numbers and symbols that we learn in school.

Development (20-25 minutes)

1. Activity 1 - "Number Hunting" (10-15 minutes)

   • The teacher should prepare cards with numbers written on them (from 1 to 1,000) and scatter them on the floor of the classroom.
   • Divided into groups, the students should take turns picking up a numbered card from the floor.
   • They should then show the card to the class and then come up with an addition or subtraction involving the number on the card and another number chosen by the group.
   • The other students in the group should solve the problem presented, using the counting, regrouping, and decomposition strategies they have learned.
   • The student who picked up the card should then check if the answer given by the group is correct. If so, the card is placed in a pile of correct cards, otherwise it is placed in a pile of incorrect cards.
   • At the end of the activity, the teacher checks the correct and incorrect cards and discusses with the class the correct solutions and the strategies used.

2. Activity 2 - "Solving Everyday Problems" (10-15 minutes)

   • The teacher should prepare a series of problems involving addition and subtraction of numbers less than 1,000 that are common in the students' daily lives. For example:
     1. "If you have $500.00 and want to buy a toy that costs $380.00, how much money will you have after buying the toy?"
     2. "You have 725 stickers and get 123 more as a gift. How many stickers will you have in total?"
   • Each group of students receives a problem and should work together to solve it. They can use paper and pencil, drawings, or other materials that help solve the problem.
   • The teacher circulates around the room, assisting the groups when necessary.
   • After a given time, each group should present the solution they found for the problem and explain the reasoning used.
   • The teacher discusses with the class the different solutions presented, reinforcing the concepts of addition and subtraction and the strategies used.

3. Activity 3 - "Addition and Subtraction Memory Game" (10-15 minutes)

   • The teacher should prepare cards with numbers and cards with addition and subtraction problems involving those numbers. For example, one card could have the number 5 and another card could have the problem "5 + 3". Another card could have the number 10 and another card could have the problem "10 - 2", and so on.
   • Divided into groups, the students should play the Memory Game, where they should try to find pairs of cards (a number and an addition or subtraction problem involving that number).
   • When a pair of cards is found, the student who found it should solve the addition or subtraction problem and show the group how they did it.
   • The game continues until all the cards are found.
   • The teacher circulates around the room, assisting the students when necessary.
   • At the end of the game, the teacher discusses with the class the different solutions presented, reinforcing the concepts of addition and subtraction and the strategies used.

Debrief (10-15 minutes)

1. Group Discussion (5-7 minutes)

   • The teacher should bring the whole class together and encourage a collective discussion about the solutions found during the activities. It is important that each group has the opportunity to share their answers and strategies used.
   • The teacher should encourage students to explain the reasoning behind their solutions, reinforcing the importance of understanding the solving process, not just the result.
   • During the discussion, the teacher should highlight the most effective strategies and encourage students to try different approaches in the future. For example, the teacher can say: "Group A used the counting strategy to solve the problem, while group B used the regrouping strategy. Both strategies are valid and help us solve addition and subtraction problems."

2. Connection with Theory (3-5 minutes)

   • The teacher should then recap the main theoretical concepts covered in the lesson, making the connection with the practical activities carried out. For example, the teacher can say: "We have learned that, to add or subtract large numbers, we can use different strategies, such as counting, regrouping, and exchanging order. We have also seen that we can apply these strategies in everyday situations, such as shopping problems or receiving gifts."
   • The teacher can reinforce these concepts by giving additional examples and asking students to explain how they can be applied.

3. Final Reflection (2-3 minutes)

   • To end the class, the teacher should propose a moment of reflection, where students will have the opportunity to think about what they have learned. The teacher can ask two simple questions to guide this reflection:
     1. "Which strategy did you enjoy using the most to solve the addition and subtraction problems?"
     2. "How can you apply what you have learned today in your everyday situations?"
   • The teacher can ask the students to share their answers, reinforcing the idea that mathematics is a useful and relevant tool in their lives.

This feedback time is essential for consolidating learning, promoting reflection and students' understanding of the concepts worked on, and encouraging autonomy and critical thinking.

Conclusion (5-10 minutes)

1. Summary of Contents (2-3 minutes)

   • The teacher should begin the conclusion by summarizing the main contents covered in the lesson. He should remind students about the addition and subtraction of natural numbers less than 1,000, as well as the different strategies that can be used to solve these operations, such as counting, grouping, and changing the order.
   • For example, the teacher can say: "Today, we learned how to add and subtract larger numbers, such as 725 and 845. We saw that we can use different strategies to solve these operations, such as counting, regrouping, and changing the order. These strategies help us solve everyday problems, such as shopping, playing games, and various other situations."

2. Connection between Theory and Practice (1-2 minutes)

   • Next, the teacher should emphasize the connection between the theory taught and the practice carried out. He should emphasize that the activities carried out in the classroom were not just abstract exercises, but rather concrete applications of the mathematical concepts learned.
   • For example, the teacher can say: "We have seen that mathematics is not just a subject that we study in school, but rather a tool that we use every day in our lives. With addition and subtraction, we can solve shopping problems, game problems, task organization problems, and many other things."

3. Extra Materials (1-2 minutes)

   • The teacher can then suggest some extra materials so that the students can deepen their understanding of the subject. These materials may include math books, educational websites with games and interactive exercises, and explanatory videos.
   • For example, the teacher can say: "If you want to learn more about addition and subtraction, I recommend the book 'Fun Math' by author Joana. This book has several games and activities that will help you practice what you learned today. In addition, you can also visit the website 'Cool Math', which has many educational games and videos on various math topics, including addition and subtraction."

4. Importance of the Subject (1-2 minutes)

   • Finally, the teacher should reinforce the importance of the subject learned, explaining that addition and subtraction are essential skills for daily life. He can mention some everyday situations where these skills are used, such as shopping, playing games, organizing tasks, and even in unexpected situations that may arise.
   • For example, the teacher can say: "Addition and subtraction are very important skills for our daily lives. We use them all the time, in shopping, in games, in organizing tasks, and even in unexpected situations. For example, if you have $10.00 and want to buy a toy that costs $7.00, you will need to subtract to find out how much money you will have left after the purchase. Or if you are making a cake and the recipe asks you to add 3 eggs to the dough, you will need to add to find out how many eggs you will use in total."

The conclusion is an important time to consolidate learning, reinforce the relevance of the content, and provide students with resources to continue learning and practicing outside the classroom.