Lesson Overview

Target Age: 6 years old (Kindergarten/1st Grade)

Time: 10–15 minutes

Setting: Small Group (3–6 students)

Topic: Place value using Base Ten blocks with a "Monster" theme.

Materials Needed

• Base Ten Blocks (Rods/Tens and Units/Ones)
• "Monster Number" cards (Numbers 11–19)
• Optional: Googly eyes or stickers to place on the blocks
• A small tray or "Monster Den" for each student

Learning Objectives

By the end of this lesson, students will be able to:

• Identify a "long" as representing 10 and a "cube" as representing 1.
• Construct numbers between 11 and 19 using one ten-rod and the correct number of units.
• Explain that the "1" in a teen number represents one group of ten.

1. Introduction: The Hungry Beast (2 Minutes)

Hook: "Friends, I have a secret! I found a group of Number Monsters under my desk! These monsters are very picky eaters. They only eat snacks in groups of ten or single treats. They are so hungry, they are starting to lose their shapes!"

The Goal: "Today, we are going to be 'Monster Builders.' We are going to use our Base Ten blocks to build bodies for our monsters so they can go to the Monster Party tonight!"

2. Body: I Do, We Do, You Do (10 Minutes)

I Do: Modeling the Build (2 Minutes)

Talking Points: "Watch me build Monster Number 12. His name is 'Twelve-er.' The number 12 has a '1' at the start. That means he has one giant body part made of 10 cubes. We call this a 'Ten Rod.' (Hold up the rod). Then, he has a '2' at the end. That means he has 2 little toes! (Place two units next to the rod). Look! One ten and two ones make 12!"

We Do: Guided Practice (3 Minutes)

Activity: Give each student a "Ten Rod."
Talking Points: "Let’s all build Monster 15 together. Everyone, hold up your Ten Rod. This is the monster’s tall spine! Now, how many toes does Monster 15 need? Look at the second number. That’s right, five! Let's count out five little cubes and put them at the bottom of our spine. Count with me: 1, 2, 3, 4, 5!"

You Do: Independent Creation (5 Minutes)

Activity: Hand out a different "Monster Number Card" (11, 13, 14, 16, 17, 18, or 19) to each student.
Instruction: "Now it’s your turn! Look at your card and build your monster's body. Use one tall Ten Rod and then the right amount of little 'ones' cubes. When you are done, you can give your monster two googly eyes!"
Success Criteria: The monster must have exactly one rod and the number of units shown in the "ones" place of their card.

3. Conclusion: The Monster Parade (3 Minutes)

Recap: "Let’s have a Monster Parade! Hold up your monster. If I say your monster's name, tell me what he is made of."
(Example: "Monster 14, what do you have?" Student: "One ten and four ones!")

Summary: "You did it! You learned that big 'teen' numbers are just one group of ten hiding with some extra friends. Now our monsters are ready for the party!"

Assessment

• Formative: During the "You Do" phase, observe if students are grabbing one rod and the correct number of units. Ask: "Why did you pick one tall stick?" (Look for: "Because it's ten.")
• Summative: Ask the student to swap cards with a neighbor and "fix" the monster to match the new number. If they can adjust the units correctly, they have mastered the concept.

Differentiation

• For Struggling Learners: Use a "Ten Frame" mat where they can place the ten-rod on one side and count the units into boxes on the other side to visualize the separation.
• For Advanced Learners: Give them a "Mega Monster" card like number 22. Ask them: "What happens if the first number is a 2? How many tall spines does he need then?" (Encourage them to use two ten-rods).