# Lesson 12

How Many Are Missing?

## Warm-up: Which One Doesn’t Belong: 10-frames (10 minutes)

### Narrative

This warm-up prompts students to carefully analyze and compare features of four images. The activity also enables the teacher to hear the terminologies students know and how they talk about characteristics of the 10-frame and compositions and decompositions of 10.

### Launch

• Groups of 2
• Display the image.
• “Pick one that doesn’t belong. Be ready to share why it doesn’t belong.”
• 1 minute: quiet think time

### Activity

• 2–3 minutes: partner discussion
• Share and record responses.

### Student Facing

Which one doesn’t belong?

### Activity Synthesis

• Display image D.
• “How many counters are there?” (10)
• “What parts do you see inside 10?” (4 and 6)
• Write $$10 = 4 + 6$$.
• “There are 10 counters, 4 red and 6 yellow. We can write that as 10 is $$4 + 6$$.”
• Invite students to chorally repeat the equation in unison 1-2 times.

## Activity 1: Shake, Spill, and Arrange with 10 (10 minutes)

### Narrative

The purpose of this activity is for students to compose and decompose 10 in multiple ways. Students shake and spill 10 counters and find an equation to match each composition and decomposition.

MLR8 Discussion Supports. Invite students to say each equation aloud. Listen for and clarify any questions about the equations.

### Required Materials

Materials to Gather

### Required Preparation

• Each group of 2 needs 1 cup and 10 two-color counters.

### Launch

• Groups of 2
• Give each group of students 10 two-color counters and a cup.
• “Take turns shaking and spilling all 10 counters. Arrange the counters in the 10-frame at the top of your page. Then put a check mark next to the equation that shows the red and yellow counters. If you get the same equation again, put another check mark next to it.”

### Activity

• 6 minutes: partner work time

### Student Facing

$$10 = 5 + 5$$

$$10 = 9 + 1$$

$$10 = 4 + 6$$

$$10 = 2 + 8$$

$$10 = 6 + 4$$

$$10 = 3 + 7$$

$$10 = 1 + 9$$

$$10 = 8 + 2$$

$$10 = 5 + 5$$

### Activity Synthesis

• Display $$10 = 8 + 2$$
• “Use your counters to show this equation.”
• “How many counters are there? What are the 2 parts that you see?” (There are 10 counters. There are 8 red counters and 2 yellow counters or 8 yellow and 2 red counters.)

## Activity 2: How Many to Fill the 10-frame? (10 minutes)

### Narrative

The purpose of this activity is for students to find how many counters are needed to fill a 10-frame. Students may count the number of empty squares or use counters to fill them. Students may be able to recognize how many counters are needed without counting. With repeated experience composing 10 in many ways, students may begin to know the combinations to make 10 (MP8).

Engagement: Develop Effort and Persistence. Chunk this task into more manageable parts. Students can work on the first half of the problems and then move on to the second half. Check-in with students to provide feedback and encouragement after the first half has been worked on.
Supports accessibility for: Organization, Attention

### Required Materials

Materials to Gather

### Launch

• Groups of 2
• “Figure out how many counters are needed to fill each 10-frame. Write a number to show how many counters are needed to fill it.”
• “Circle the equation that shows the number of counters in the 10-frame and the number of counters needed to fill the 10-frame.”

### Activity

• 3 minutes: independent work time
• 3 minutes: partner work time

### Student Facing

1.

_______________

$$10 = 7 + 3$$

$$10 = 8 + 2$$

$$10 = 5 + 5$$

2.

_______________

$$10 = 8 + 2$$

$$10 = 1 + 9$$

$$10 = 4 + 6$$

3.

_______________

$$10 = 9 + 1$$

$$10 = 5 + 5$$

$$10 = 7 + 3$$

4.

_______________

$$10 = 5 + 5$$

$$10 = 3 + 7$$

$$10 = 2 + 8$$

5.

_______________

$$10 = 9 + 1$$

$$10 = 6 + 4$$

$$10 = 5 + 5$$

6.

_______________

$$10 = 1 + 9$$

$$10 = 2 + 8$$

$$10 = 4 + 6$$

### Activity Synthesis

• Display the image of 2 counters on a 10-frame.
• “Which equation did you circle for this 10-frame? Why?” (I circled $$10 = 2 + 8$$ because there are 2 red counters on the 10 frame. There are 8 empty squares, so I need 8 more counters to fill in the 10 frame.)
• Write $$10 = 2 + 8$$.
• “What does the 10 in this equation show?” (There are 10 squares in the 10-frame.)

## Activity 3: Centers: Choice Time (25 minutes)

### Narrative

The purpose of this activity is for students to choose from activities that offer practice with counting, adding, composing, and decomposing numbers.

Students choose from any stage of previously introduced centers.

• Shake and Spill
• Counting Collections

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from:
• Shake and Spill, Stages 1–3
• Counting Collections, Stage 1
• Roll and Add, Stages 1 and 2

### Launch

• “Today we 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.
• 10 minutes: center work time
• “Choose what you would like to do next.”
• 10 minutes: center work time

### Student Facing

Choose a center.

Shake and Spill

Counting Collections

### Activity Synthesis

• “Have you ever been disappointed when it was time to switch or end centers because you wanted to keep playing? What did you do?”

## Lesson Synthesis

### Lesson Synthesis

Display a 10-frame with 5 red counters.

“Jada spilled 10 counters. Here are the red counters Jada got when she was playing Shake and Spill.”

“How many yellow counters did Jada get? How do you know?” (The yellow counters fit in all the rest of the squares. There are 5 empty squares. She spilled 10 counters so the 10-frame should be full.)

Demonstrate filling the 10-frame with 5 yellow counters.

“What equation can we use to show Jada’s counters?” ($$10 = 5 + 5$$)

If needed, ask “How many counters are on the 10-frame? What are the 2 parts that you see?”