**Lesson Plan: Least Common Multiples (LCM)**
**Grade Level**: Primary 4
**Subject**: Mathematics
**Topic**: Least Common Multiples (LCM)
**Duration**: 60 minutes
---
### Objectives:
1. **Knowledge**: Students will understand the concept of multiples and the least common multiple.
2. **Skills**: Students will be able to find the LCM of two or more numbers.
3. **Attitude**: Students will appreciate the use and importance of LCM in problem-solving.
### Materials Needed:
- Whiteboard and markers
- Chart paper and markers
- Number cards
- Interactive worksheets
- Small whiteboards and dry-erase markers for each student
### Common Core State Standards:
- **CCSS.MATH.CONTENT.4.OA.B.4**: Find all factor pairs for a whole number in the range 1-100. Recognize that a whole number is a multiple of each of its factors. Determine whether a given whole number is a multiple of a given one-digit number. Determine whether a given whole number is prime or composite.
### Lesson Activities:
#### Introduction (10 minutes):
1. **Warm-up**:
- Begin with a brief review of multiplication tables.
- Ask students what they remember about multiples and have a few volunteers give examples.
- Write a few numbers on the board (e.g., 3, 5, 4) and ask students to list the first five multiples of each number.
#### Direct Instruction (15 minutes):
1. **Explain Multiples**:
- Define a multiple: A multiple of a number is the product of that number and an integer.
- Provide examples: "The multiples of 3 are 3, 6, 9, 12, …”
2. **Introduce LCM**:
- Define the Least Common Multiple (LCM): The smallest multiple that two or more numbers have in common.
- Explain the importance of LCM in solving real-world problems like finding common times for events, sharing things equally, etc.
3. **Steps to Find LCM**:
- List the multiples of each number.
- Find the common multiples.
- Identify the smallest common multiple.
#### Guided Practice (15 minutes):
1. **Class Activity**:
- Pair students and give them number cards (sets of 1-10).
- Ask pairs to choose two numbers and find the LCM using the steps discussed.
- Circulate the classroom to provide assistance and check for understanding.
#### Independent Practice (10 minutes):
1. **Worksheets**:
- Distribute interactive worksheets where students find the LCM of various pairs of numbers.
- Include a mix of easy and challenging problems to cater to different skill levels.
#### Closure (5 minutes):
1. **Review and Reflect**:
- Summarize the day's lesson on the whiteboard.
- Discuss any questions or difficulties students encountered.
- Reinforce the utility of LCM in everyday situations.
#### Assessment (5 minutes):
1. **Quick Quiz**:
- Give a short quiz with 3-5 questions to evaluate students' understanding.
- Example questions:
- Find the LCM of 4 and 6.
- Find the LCM of 5 and 10.
- Describe in your own words what LCM means.
### Differentiated Instruction:
- **For Advanced Students**: Introduce the concept of LCM using prime factorization as an optional challenge.
- **For Struggling Students**: Provide additional practice with fewer and smaller numbers, and pair them with peers for support.
### Homework:
- Provide students with a worksheet to practice finding LCMs of different pairs of numbers.
- Encourage them to explain the steps they took to solve each problem.
### Teacher's Reflection:
- After the lesson, reflect on what worked well and what did not.
- Note any students who may need additional support or enrichment.
- Adjust future lessons based on observed student understanding and engagement.
### Follow-Up:
- Plan a follow-up lesson to reinforce LCM concepts, perhaps integrating word problems or real-life applications.
---
By the end of this lesson, students should be comfortable finding the LCM of two or more numbers and understand its practical value.