# Lesson 11

Equations that Show 10

## Warm-up: Notice and Wonder: Expressions for 10 (10 minutes)

### Narrative

The purpose of this warm-up is to elicit the idea that expressions and equations can be used to represent different compositions and decompositions of 10, which will be useful when students match compositions and decompositions of 10 to equations in a later activity. While students may notice and wonder many things about these images and expressions, the fact that each image and expression represents a total of 10 is the important discussion point. Students have seen equations in previous lessons, but the synthesis is the first time that students are introduced to the term equation.

### Launch

• Groups of 2
• Display the image.
• “What do you notice? What do you wonder?”
• 1 minute: quiet think time

### Activity

• 1 minute: partner discussion
• Share and record responses.

### Student Facing

What do you notice?
What do you wonder?

$$7 + 3$$

$$5 + 5$$

$$8 + 2$$

### Activity Synthesis

• “What is the same about each expression?” (They are all 10.)
• Write $$10 = 7 + 3$$.
• “There are 10 counters, 7 red counters and 3 yellow counters. We can write that as 10 is 7 plus 3. When we write $$10 = 7 + 3$$, it is called an equation.”
• Repeat the steps with the next 2 images.

## Activity 1: Match Equations and 10-frames (10 minutes)

### Narrative

The purpose of this activity is for students to match equations to compositions and decompositions of 10 on 10-frames.
MLR8 Discussion Supports. Students should take turns matching each 10-frame to the equation and explaining their reasoning to their partner. Display and read the following sentence frames: “I noticed _____, so I matched . . . .” Encourage students to challenge each other when they disagree.

### Launch

• Groups of 2
• “Draw a line from each 10-frame to the equation it matches.”

### Activity

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

### Student Facing

1.
2.
3.
4.
5.

$$10 = 7 + 3$$

$$10 = 8 + 2$$

$$10 = 1 + 9$$

$$10 = 4 + 6$$

$$10 = 5 + 5$$

### Student Response

If students match the 10-frame with 8 red counters and 2 yellow counters to an equation other than $$10 = 8 + 2$$, consider asking:
• “What 2 parts do you see on the 10-frame?”
• “What 2 parts do you see in each equation? Can you find an equation that shows the same parts that you see in the 10-frame?”

### Activity Synthesis

• Invite students to share which equation they matched to the first three 10-frames.
• “How many counters are on this 10-frame?” (10)
• “What are the 2 parts that you see?” (5 yellow and 5 red)
• “There are 10 counters, 5 yellow counters and 5 red counters. 10 is 5 plus 5.”
• Invite students to chorally repeat these equations in unison 1–2 times.

## Activity 2: Represent Equations with Fingers (10 minutes)

### Narrative

The purpose of this activity is for students to represent equations on fingers. In this activity, students become more comfortable recognizing and representing compositions and decompositions of 10 on their fingers. In future lessons, students may choose to use their fingers to help them find the number that makes 10 when added to a given number. In the activity synthesis, students consider how 2 different drawings can represent the same equation.

Representation: Develop Language and Symbols. Synthesis: Make connections between both representations visible: fingers and equations. Invite students to identify where a number in the equation is represented in the finger drawing and vice versa.
Supports accessibility for: Visual-Spatial Processing, Organization

### Required Materials

Materials to Gather

### Required Preparation

• Each student needs at least 2 different colored crayons.

### Launch

• Groups of 2
• Give each student at least 2 different colored crayons.
• “Color the fingers to show each equation.”

### Activity

• 3 minutes: independent work time
• “As you continue working, tell your partner about the total and the 2 parts you colored in each set of fingers.”
• 3 minutes: partner work time

### Student Facing

$$10 = 6 + 4$$

$$10 = 9 + 1$$

$$10 = 5 + 5$$

$$10 = 3 + 7$$

$$10 = 8 + 2$$

$$10 = 1 + 9$$

### Student Response

If students color all of the fingers one color to represent $$10 = 1 + 9$$, consider asking:
• “What are the 2 parts that you see in the equation?”
• “How can you show the 2 different parts from the equation on the fingers? Which fingers show 1 from the equation? Which fingers show 9?”

### Activity Synthesis

• Write $$10 = 8 + 2$$.
• Display a set of hands with 8 fingers colored blue and 2 fingers colored red.
• Display a set of hands with 8 fingers colored red and 2 fingers colored blue.
• “What is the same about how Elena and Tyler colored their hands? What is different about them?” (They both colored 8 and 2. Elena colored 8 blue and 2 red. Tyler colored 8 red and 2 blue.)

## 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

• “Which center did you choose today? What did you get better at while working in the center?”

## Lesson Synthesis

### Lesson Synthesis

“Today we used equations to show many different ways to make 10.”

Write $$10 = 9 + 1$$.

Display a 10-frame with 9 red counters and 1 yellow counter.

Hold up 9 fingers.

“Where do you see 10 on the 10-frame and on the fingers?” (There are 10 counters on the 10-frame. There are 10 fingers.)

“Where do you see 9? Where do you see 1?” (There are 9 red counters and 9 fingers up. There is 1 yellow counter and 1 finger down.)