### Lesson Plan: The Concept of 100
#### Grade Level: Primary 2
#### Subject: Mathematics
#### Duration: 60 minutes
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#### Objectives:
By the end of the lesson, students will be able to:
1. Understand the concept of 100 as a number.
2. Count to 100 by ones and tens.
3. Recognize and write the number 100.
4. Understand the significance of grouping in tens to reach 100.
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#### Materials Needed:
- 100 counters (like buttons, beans, or small blocks)
- Chart paper
- Markers
- Base-ten blocks (unit cubes, tens rods)
- Pencils
- Number charts (1-100)
- Worksheets with counting exercises
- Interactive whiteboard (if available)
- "Hundred Number" song (optional)
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#### Lesson Steps:
**1. Introduction (10 minutes)**
- Begin with a warm-up exercise where students count from 1 to 20 together.
- Explain that today, they will learn about the number that comes after all these numbers, which is 100.
**2. Direct Instruction (15 minutes)**
- Show students 100 counters and ask them to guess how many there are. Discuss their guesses.
- Using a whiteboard or chart paper, write the number 100 and explain its place value (1 in hundreds place, 0 in tens and ones places).
- Demonstrate counting to 100 by ones. Use a number chart for visual aid.
- Discuss how 100 is a big number that is reached by counting ten groups of ten. Use base-ten blocks to visually show this concept: ten rods (each rod represents 10 unit cubes) equals 100 unit cubes.
**3. Guided Practice (15 minutes)**
- Sing a “Hundred Number” song or use an interactive counting video that counts to 100 by ones and tens.
- Hand out base-ten blocks and number charts to students. Guide them in grouping unit cubes into tens, and then into one group of 100.
- Practice counting by tens aloud as a class and point to the corresponding numbers on a number chart.
**4. Independent Practice (10 minutes)**
- Provide worksheets where students practice writing the numbers up to 100.
- Include exercises that involve counting objects and circling groups of 10.
- Have students count their own sets of 100 counters, grouping them into tens first, and then verifying their total by counting to 100 by ones.
**5. Review and Closing (10 minutes)**
- Review what the students learned about the number 100.
- Ask a few students to come up and demonstrate counting to 100 by ones or tens.
- Allow students to share something they found interesting or challenging about reaching or visualizing 100.
**6. Reflection (Optional)**
- As a class, create a “100” collage: each student contributes ten items they can count (e.g., stickers, dots, stamps) to make a visual representation of 100.
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#### Assessment:
- Observe students during guided practice to ensure understanding.
- Review completed worksheets to assess counting and writing skills.
- Conduct a quick oral quiz asking students to count by tens to 100 and recognize the number 100.
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#### Differentiation:
- For students who grasp the concept quickly, provide additional challenges like counting backwards from 100 or skip counting by fives.
- For students who need extra help, offer more hands-on practice with manipulatives and one-on-one support.
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#### Homework:
- Assign students to find and count 100 small items at home (e.g., beans, pasta) and group them in tens, writing down their observations for the next class.
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By the end of the lesson, students should have a concrete understanding of the number 100, how to count to it, and its place in the number system.