Lesson Plan | Lesson Plan Tradisional | Addition and Subtraction of Natural Numbers Less than 100

Objectives

Duration: 10 - 15 minutes

The aim of this lesson plan stage is to provide a clear and structured overview of what will be taught in class. By outlining specific objectives, the teacher sets a clear path, ensuring that both the teacher and the learners are on the same page regarding the skills that will be developed. This promotes effective classroom management and helps learners see the relevance of what they’re learning.

Objectives Utama:

1. Teach learners to add two-digit numbers with and without algorithms.

2. Teach learners to subtract two-digit numbers with and without algorithms.

3. Enable learners to solve problems that involve adding or subtracting two-digit numbers.

Introduction

Duration: 10 - 15 minutes

The goal of this stage is to ignite the learners’ interest and provide context for the topic, showcasing how vital addition and subtraction are in everyday scenarios. This approach helps make learning more meaningful and relevant, boosting their motivation to engage.

Did you know?

Did you know that addition and subtraction are operations that have been used since ancient times? The ancient Egyptians already applied these techniques for building pyramids and managing their crops. Today, we use addition and subtraction in many fields, from science and engineering to video game design!

Contextualization

To kick off our lesson on the addition and subtraction of natural numbers less than 100, let’s think about some everyday scenarios where we use these skills. For instance, when you go shopping with your family and need to tally the prices of items to figure out the total cost, or when you get change back and need to check if it adds up correctly. These operations are essential and very handy for tackling various problems we come across daily.

Concepts

Duration: 50 - 60 minutes

This part of the lesson is designed to provide thorough explanations of addition and subtraction concepts, as well as to guide learners in problem-solving. By clearly addressing each topic with practical examples, the teacher ensures that learners grasp and can apply the mathematical operations accurately. Solving questions together allows learners to practice and solidify their understanding.

Relevant Topics

1. Concept of Addition: Explain to learners that addition is the mathematical operation of combining two or more quantities. Use classroom items, like pencils or erasers, for illustration. For example, 'If we have 3 pencils and we add 2 more, how many pencils do we have altogether?'

2. Concept of Subtraction: Describe subtraction as the operation of taking away one quantity from another. Use visual aids, such as drawing apples on the board. For example, 'If we start with 5 apples and eat 2, how many apples are left?'

3. Adding Two-Digit Numbers: Teach how to add two-digit numbers, beginning with the units and progressing to the tens. Use examples like '23 + 45' on the board. Walk them through step-by-step, starting with the units (3 + 5 = 8) and then the tens (2 + 4 = 6), leading to a total of 68.

4. Subtracting Two-Digit Numbers: Explain the subtraction of two-digit numbers. Use examples like '76 - 34' on the board. Detail the process starting with the units (6 - 4 = 2) and then the tens (7 - 3 = 4), resulting in a total of 42.

5. Problem Solving: Offer contextualised problems involving addition and subtraction such as: 'If John had R50 and spent R23 at the shop, how much money does he have left?' or 'Ana had 37 stickers and received 25 more from a friend. How many stickers does Ana have now?'

To Reinforce Learning

1. Calculate: 47 + 32

2. Calculate: 58 - 19

3. John had 45 sweets and gave 17 to his friend. How many sweets does John have now?

Feedback

Duration: 15 - 20 minutes

This stage focuses on reviewing and reinforcing the concepts of addition and subtraction, ensuring that all learners have understood. The in-depth discussion of questions helps identify and rectify errors, encourages active participation, and fortifies understanding through collective engagement.

Diskusi Concepts

1. Question 1: Calculate: 47 + 32

Explanation: To solve 47 + 32, you follow these steps: Add the units: 7 + 2 = 9. Add the tens: 4 + 3 = 7.

So, 47 + 32 = 79.

Question 2: Calculate: 58 - 19

Explanation: For 58 - 19, follow these steps: Subtract the units: 8 - 9. Since 8 is smaller than 9, we need to borrow from the tens column. Thus, convert it to 18 - 9 = 9. Subtract the tens: After borrowing, 4 (the remaining tens) becomes 4 - 1 = 3.

So, 58 - 19 = 39.

Question 3: John had 45 sweets and gave away 17. How many sweets does he have now?

Explanation: To solve this, perform the subtraction of 45 - 17: Subtract the units: 5 - 7. Since 5 is less than 7, borrow from the tens: this becomes 15 - 7 = 8. Subtract the tens: After borrowing, 3 becomes 3 - 1 = 2.

So, John has 28 sweets now.

Engaging Students

1. Has anyone calculated a different answer for the sum of 47 + 32? How did you get to that answer? 2. Did anyone struggle with the subtraction of 58 - 19? What parts did you find difficult? 3. How can we verify if our subtraction of 45 - 17 is accurate? 4. In what other daily scenarios do you use addition and subtraction? Can anyone share an example? 5. If John had given away 20 sweets instead of 17, how many would he have now? How do we work that out?

Conclusion

Duration: 5 - 10 minutes

This stage serves to review and summarise key points from the lesson, ensuring students leave with a clear and well-organised understanding of the material. The conclusion also reinforces the link between theory and practice, underscoring the relevance of what they’ve learned for everyday life.

Summary

['The concept of addition as the operation of combining quantities.', 'The concept of subtraction as the operation of taking quantities away.', 'Adding two-digit numbers by summing units and tens separately.', 'Subtracting two-digit numbers and borrowing when needed.', 'Solving practical problems involving the addition and subtraction of two-digit numbers.']

Connection

Throughout the lesson, we illustrated how addition and subtraction apply in various everyday contexts, such as calculating change, adding up prices at the shops, and resolving practical issues. Visual aids and contextualised problems assisted in connecting mathematical concepts to real life, boosting learners' understanding and ability to apply what they've learned.

Theme Relevance

Mastering addition and subtraction of two-digit numbers is essential for learners in their daily lives. These skills are used in regular activities, such as shopping, handling money, and even in games. Learning these operations early on equips students with crucial mathematical skills they'll use throughout their lives.