# Lesson 6

## Warm-up: Notice and Wonder: The Fish Tank (10 minutes)

### Narrative

The purpose of this warm-up is for students to make sense of the structure of a story problem, which will be useful when students solve story problems and write equations in a later activity. The problem does not have numbers, so the focus can remain on making sense of the problem, rather than computing.

### Launch

• Groups of 2
• Display the statements.
• “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?

There are some fish in the tank.
Some of the fish are red and some are blue.

### Student Response

For access, consult one of our IM Certified Partners.

### Activity Synthesis

• “Where might numbers fit into this story problem?” (To tell the number of red fish and the number of blue fish. To tell how many fish there are in all.)

## Activity 1: Three Reads: Kiran’s Fish (15 minutes)

### Narrative

The purpose of this activity is to reintroduce students to Put Together, Total Unknown story problems. In this type of problem, there is no action, so students must recognize the addends must be joined to make up the total. Students were introduced to this type of story problem in kindergarten and solved within 10 using objects or drawings. Students also solved Put Together, Total Unknown problems in Unit 1 in the context of data.

Students begin the activity by looking at the problem displayed, rather than in their books. The three reads routine gives students an opportunity to make sense of the problem before looking for a solution. Because there is no action in a put together problem, students identify the important quantities and think about how they might represent them before they solve the problem (MP1). At the end of the launch, students open their books and work on the problem. Students solve in any way they choose including using objects, drawings, words, or numbers, and write an equation to match the story problem.

### Required Materials

Materials to Gather

### Launch

• Groups of 2
• Give students access to 10-frames and connecting cubes or two-color counters.

### Activity

• Display only the problem stem, without revealing the question(s).
• “We are going to read this problem 3 times.”
• 1st Read: “Kiran has some fish in his fish tank. He has 4 red fish and 5 blue fish.”
• “What is this story about?”
• 1 minute: partner discussion
• Listen for and clarify any questions about the context.
• 2nd Read: “Kiran has some fish in his fish tank. He has 4 red fish and 5 blue fish.”
• “What are all the things we can count in this story?” (the number of red fish, the number of blue fish, the total number of fish)
• 30 seconds: quiet think time
• 2 minutes: partner discussion
• Share and record all quantities.
• Reveal the question(s).
• “What are different ways we can solve this problem?” (I can use red and blue connecting cubes. I can draw the fish and count them.)
• 30 seconds: quiet think time
• 1 minute: partner discussion
• "Solve the problem."
• 3 minutes: independent work time
• 2 minutes: partner discussion
• Monitor for students who solve in the following ways and can explain their thinking clearly:
• objects or drawings and count all
• objects or drawings and count on
• numbers and count on

### Student Facing

Kiran has some fish in his fish tank.
He has 4 red fish and 5 blue fish.
How many fish does he have in all?
Show your thinking using drawings, numbers, or words.

Equation: ________________________________

### Student Response

For access, consult one of our IM Certified Partners.

### Activity Synthesis

• Invite previously identified students to share in sequence above.
• After each student shares, “How does this representation match the story problem?”
• Display $$4+5=\boxed{9}$$.
• "Where do you see the parts of this equation in this representation? The story problem?” (4 means the 4 red fish, 5 is the blue fish, 9 is how many he has altogether.)

## Activity 2: Tyler's and Clare’s Pets (10 minutes)

### Narrative

The purpose of this activity is for students to consider two different equations that represent the same story problem. Put Together, Result Unknown problems help students make sense of the commutative property because the two parts can be combined in different orders. This property, as well as the associative property, is referred to as “add in any order” to students. Students contextualize the problem and see that each number represents a specific object’s quantity, no matter which order it is presented, and connect these quantities to written symbols (MP2). Students will work more with the “add in any order” property in future lessons.

Representation: Access for Perception. Students may benefit from hearing the instructions read aloud more than once.
Supports accessibility for: Language, Attention

### Required Materials

Materials to Gather

### Launch

• Groups of 2
• Give students access to 10-frames and connecting cubes or two-color counters.
• “We just solved a problem about pet fish. What else do you know about pets?”
• 30 seconds: quiet think time
• 1 minute: partner discussion
• If needed ask, “What kinds of pets are there?”

### Activity

• 3 minutes: independent work time
• 2 minutes: partner discussion
• Monitor for a student who uses objects or drawings to show that each equation matches the story.

### Student Facing

Tyler and Clare want to know how many pets they have together.
Tyler has 2 turtles.
Clare has 4 dogs.

Tyler wrote the equation $$4 + 2= \boxed{6}$$.
Clare wrote the equation $$2 + 4 = \boxed{6}$$.

Do both equations match the story?
Why or why not?
Show your thinking using drawings, numbers, or words.

### Student Response

For access, consult one of our IM Certified Partners.

If students explain that both equations match the story using only numbers, consider asking:

• "How do you know that both equations match the story?"
• "How could you use connecting cubes to show that they both match?"

### Activity Synthesis

• Invite previously identified students to share.
• “How does their work show us that Tyler’s equation matches the story?”
• “How does their work show us that Clare’s equation matches the story?”

## Activity 3: Centers: Choice Time (15 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.

• Math Stories
• Find the Pair
• What’s Behind My Back

### Required Materials

Materials to Gather

### Required Preparation

• Gather materials from previous centers:
• Math Stories, Stage 4
• Find the Pair, Stage 2
• What's Behind My Back, Stage 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.”
• 30 seconds: quiet think time

### Activity

• Invite students to work at the center of their choice.
• 10 minutes: center work time

### Student Facing

Choose a center.

Math Stories

Find the Pair

What’s Behind My Back

### Activity Synthesis

• Display a picture from the Math Stories center or from a picture book.
• If needed, share a Put Together story with the class.

## Lesson Synthesis

### Lesson Synthesis

Display the story about fish in the tank.

"Today we saw two different equations that matched the same story. What are two equations that match this story?" (4 + 5 = 9 and 5 + 4 = 9)

Use 4 red cubes and 5 blue cubes to show beginning with either one, and adding the other, leads to the same total.

## Cool-down: Unit 2, Section B Checkpoint (0 minutes)

### Cool-Down

For access, consult one of our IM Certified Partners.