# Lesson 10

Center Day 2

## Warm-up: Number Talk: Subtraction Methods (10 minutes)

### Narrative

The purpose of this Number Talk is to elicit strategies and understandings students have for adding or subtracting 1 or 2 to a given number. Students may use what they know about the count sequence to find the answer (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 problems and work displayed.
• Repeat with each expression.

### Student Facing

Find the value of each expression mentally.

• $$7 - 2$$
• $$8 - 2$$
• $$7 - 5$$
• $$8 - 6$$

### Activity Synthesis

• “How are problems 2 and 4 the same? How are they different?” (They both start with 8. The missing number is in the same place. They subtract different numbers. They use the same 3 numbers.)

## Activity 1: Introduce Capture Squares, Add Within 10 (20 minutes)

### Narrative

The purpose of this activity is for students to learn a new center called Capture Squares. Students roll two number cubes and find the sum using math tools or mental methods they have developed during the unit. They connect two dots that are adjacent to the number. If that line closes the square, they capture it and shade it in their color. The player to shade in three squares first is the winner.

MLR8 Discussion Supports. Invite students to play the game and take turns asking the question, “What is the sum and how do you know?”. This gives both students an opportunity to produce language.
Representation: Develop Language and Symbols. Synthesis: Invite students to explain their thinking orally, using connecting cubes, two-color counters, or using pictures.
Supports accessibility for: Conceptual Processing, Language, Visual Spatial Processing

### Required Materials

Materials to Gather

Materials to Copy

• Capture Squares Stage 1 Gameboard

### Launch

• Groups of 2
• Give each group two number cubes, two different colored crayons or colored pencils, a game board, and access to 10-frames and connecting cubes or two-color counters.
• "We are going to learn a new game called Capture Squares. Let’s play a round together.”
• Roll the number cubes.
• “What is the sum and how do you know?”
• 30 seconds: quiet think time
• 30 seconds: partner discussion
• Share responses.
• “Now I find the square that has the sum. I draw a line connecting two dots on that square.”
• Repeat 1–2 more times, as needed.
• “If I draw the line that completes the square, I shade in that square my color. The first person to shade in three squares wins."

### Activity

• 12 minutes: partner work time

### Activity Synthesis

• Display a game board with a couple of squares shaded. Draw three lines around the 8 so one more is needed to fill in the square.
• “What numbers could I roll on the number cubes that would allow me to capture the square with the 8? (2 and 6, 4 and 4, 3 and 5)

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

### Narrative

The purpose of this activity is for students to choose from activities that offer practice telling and solving story problems and adding and subtracting within 10. Students choose from any stage of previously introduced centers.

• Math Stories
• Shake and Spill
• Capture Squares

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from previous centers:
• Math Stories, Stage 4
• Shake and Spill, Stages 3 and 4
• Capture Squares, Stage 1

### Launch

• Groups of 2
• "Now you will choose from centers we have already learned. One of the choices is to continue playing Capture Squares."
• 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

Choose a center.

Math Stories

Shake and Spill

Capture Squares

### Activity Synthesis

• “What is one thing you learned or got better at by working on the activity you chose?”

## Lesson Synthesis

### Lesson Synthesis

“Today we chose activities to work on and worked with a partner during center time.”

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