## Decompose Numbers - Section 3: Guided Practice

*Decompose Numbers*

*Decompose Numbers*

# Snap Apart 5

Lesson 4 of 4

## Objective: SWBAT find combinations that make 5 by breaking apart 5 towers and naming the parts.

## Big Idea: Kindergartners need a concrete understanding of what it means to decompose and compose numbers to 10. Combinations for 2, 3 and 4 are easy for them, but 5 and above is struggle every year. This activity makes it fun to learn.

*60 minutes*

Each day we begin our math block with an interactive online calendar followed by counting songs and videos.

**Calendar Time:**

We do calendar on Starfall every afternoon. This website has free reading and math resources for primary teachers. It also has a “more” option that requires paying a yearly fee. The calendar use is free. A detailed description of Daily Calendar math is included in the resources.

**Counting with online sources:** Today we did counting practice to reinforce the counting skills. We watched two to three number recognition 0-10 videos (one to two minutes each) because some of my students students were still struggling with identifying numbers correctly in random order. We watched "Shawn the Train" and counted objects with him to refresh our memories on how to count objects to ten and to reinforce one to one counting. Since we have started the second quarter of the school year, we added to today's counting practice: counting to 20 forward and back, counting by tens to 100 and counting to 100 by ones to get a jump on our end of the year goals.

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#### Direct Instruction

*10 min*

I introduce this lesson by reading a story. Any "5 story" works, such as *5 Little Ducks*, *5 Little Monkeys*, or *5 Little Monsters*. I chose to read *5 Little Ducks*. I think aloud about the combinations that make 5 as I read.

Me: *Oh look, one of the little ducks got lost and didn't come back. How many little ducks did we start with?*

Students: 5

Me: *Well one got lost, so how many are their now?*

Students: 4

Me: *So 1 lost little duck and 4 little ducks right *(gesture)* here is the same as 5. I sure hope that lost little duck comes back.*

I do the same "thinking" for the combinations of 3 and 2 and 4 and 1. At the end all of the little ducks return so I use the combination of 5 and 0.

#### Resources

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#### Guided Practice

*15 min*

After we read our counting 5 book, we practice decomposing 5 to see what combinations we can come up with that make 5. We use counting/snapping cubes because it is hands-on and the kids can actually see, feel and describe what happens when the decompose 5 by sharing the combinations they make. I am watching to see who can follow the concept of decomposing and describing what happens when a number is taken apart. This skill allows students to have a deeper understanding of addition and subtraction.

My high kids enjoy doing this activity as much as my struggling kids because they enjoy using the counting/snapping cubes.

I have my helper of the day pass out a bag of counting/snapping cubes to each student. A good management tip is to have the helper give the kids close to each other on trhe floor different color cubes so you can keep an eye on who is using the materials properly and it is much easier for clean up. Each bag has 10 of the same color cubes in it.

I ask the kids to take out 5 cubes and build a tower. I ask them to hold their tower in the air once it is built. Once everyone has a tower, I ask them to close their eyes, break the tower and look to see what combination they have randomly made.

I choose students to call on to share their combinations by pulling name sticks from a name stick can.

The idea is to get kids to understand that they still have 5 blocks in their hands even though they are found within two groups.

After the kids share their combination, we repeat it back to them in this format, "2 and 3 is 5."

Me: Hold your 5 tower up in the air. Close your eyes. Break your tower into two pieces.

Kids follow the directions.

Me: Calling on a random student from the name stick can, I ask what combination he had.

Student: I have 3 and 2.

Me: And what does 3 and 2 make.

Student: He counts the cubes altogether and answers 5.

Me: Good job, let's write that on our tree map. When I asked you what 3 and 2 makes, did you have to count your cubes?

Student: Yes

Me: How many cubes to you have out of the bag?

Student: 5

Me: Okay, so if you have 5 cubes in a tower and you break the tower apart, did you lose any of your cubes?

Student: No, they are all still here.

Me: Then maybe we don't have to count them each time. If we know we have 5 cubes and we are just breaking them apart, then we still have 5 cubes so we can just say 3 and 2 make 5. Does that make sense?

Student: Kind of, but I like to count them.

Me: Then that's okay. If you're comfortable counting them, then for now continue to count them.

We continue this activity until time runs out. Once we have all the possible combinations on the tree map, we just discuss the combinations to further our understanding of what makes 5.

#### Resources

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#### Closure

*10 min*

We remain on the floor and I ask some key questions:

*What did you learn?*

*How do you know that combination makes 5?*

*What are some other ways we can make combinations of 5?*

I choose students to answer by randomly drawing their names from name stick can. This prevents me from overlooking students and from being bias and calling on only those who I know can answer the questions with clarity.

For the first question, I list on a poster (tree map) combinations that make 3, 4, and 5 when the kids share them in our discussion.

I watch and listen for kids who are confused throughout our conversation. I meet with those kids at a later time to clear up any misunderstandings and to provide small group guided practice.

#### Resources

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#### Exit Ticket

*10 min*

The exit ticket for this lesson is simple. I ask each child to show me a combination (using the blocks) that makes 5. All they have to do is replicate the activity we did in whole group and break a 5 tower apart. Then they tell me what they have based on the 2 towers they have after they break the 5 apart. The goal of this exit ticket is to check if they understand the simple concept of decomposing a number.

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- UNIT 1: Make it Count!
- UNIT 2: It All Adds Up!
- UNIT 3: Sorting & Classifying
- UNIT 4: Learning Numbers 11-19
- UNIT 5: Make It Count!
- UNIT 6: Count & Compare
- UNIT 7: Take it Away! (all about subtraction)
- UNIT 8: Know Those Shapes!
- UNIT 9: Subtraction, Subtraction...We all love subtraction!
- UNIT 10: What Makes 10?
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- UNIT 12: What Makes 5?
- UNIT 13: How Does It All Measure Up?
- UNIT 14: Fact Families
- UNIT 15: Add It or Subtract It?