# Lesson 8

Center Day 1

## Warm-up: Number Talk: Add 3 Numbers (10 minutes)

### Narrative

The purpose of this Number Talk is to elicit strategies and understandings students have for adding three one-digit numbers within 20. When students look for ways to decompose addends to make a ten with another addend, and add the remaining addends to find the sum, they look for and make use of the structure of numbers and properties of operations (MP7).

### Launch

• Display one expression.
• “Give me a signal when you have an answer and can explain how you got it.”
• 1 minute: quiet think time

### Activity

• Keep expressions and work displayed.
• Repeat with each expression.

### Student Facing

Find the value of each expression mentally.

• $$6 + 4 + 8$$
• $$6 + 8 + 4$$
• $$6 + 8 + 5$$
• $$6 + 5 + 9$$

### Activity Synthesis

• “Who can restate _____'s reasoning in a different way?”
• “Did anyone have the same strategy but would explain it differently?”
• “Did anyone approach the problem in a different way?”

## Activity 1: Introduce Match Mine, Solid Shapes (20 minutes)

### Narrative

The purpose of this activity is for students to learn stage 2 of the Match Mine center introduced in kindergarten. Students put solid shapes together to make a larger object. They hide their object behind a folder and describe it to a partner who tries to match it.

### Required Materials

Materials to Gather

### Launch

• Groups of 2
• Give each group solid shapes and a folder.
• “We are going to learn a new way to play Match Mine, which is a center that was introduced in kindergarten. Let’s play one round together. You can all be my partner.”
• Put shapes together to make an object. Hide the object behind a folder.
• “One person starts by putting shapes together to build something new. They hide their object behind the folder so their partner can’t see it. Then they describe their object to their partner, who tries to match it. I will describe my object and you can try to match it.”
• Describe your object and allow students to try to match it with the shapes.
• Discuss what you said that helped students match the object, and what you said that might not have helped.

### Activity

• “Now you will play with your partner.”
• 10 minutes: partner work time

### Activity Synthesis

• “What did your partner do or say to make it easier to match their object?” (My partner only used four blocks so it was easy to match his object. My partner told me when to put a block on top of another block or next to it.)

## Activity 2: Centers: Choice Time (20 minutes)

### Narrative

The purpose of this activity is for students to choose from activities that offer practice adding and subtracting or working with shapes. Students choose from any stage of previously introduced centers.

• Picture Books
• How Are They the Same
• Capture Squares

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from previous centers:
• Picture Books, Stage 2
• How Are They the Same, Stage 1
• Capture Squares, Stages 1 and 2

### Launch

• Groups of 2
• “Now you are going to choose from centers we have already learned.”
• Display the center choices in the student book.
• “Think about what you would like to do first.”
• 30 seconds: quiet think time

### Activity

• Invite students to work at the center of their choice.
• 8 minutes: center work time
• “Choose what you would like to do next.”
• 8 minutes: center work time

### Student Facing

Choose a center.

Picture Books

How Are They the Same?

Capture Squares

### Activity Synthesis

• “What did the centers you worked on today help you practice?”

## Lesson Synthesis

### Lesson Synthesis

“How did you and your partner work together during centers? What went well? What can we continue to work on?”