# Lesson 2

Story Problems and Equations

## Warm-up: Number Talk: Adding 1 More (10 minutes)

### Narrative

The purpose of this Number Talk is to elicit strategies and understandings students have for related expressions where an addend is 1 more than in the previous expression. These understandings help students develop fluency and will be helpful later in this lesson when students add within 10. When students notice how adding 1 to an addend increases the sum by 1 they are noticing a pattern and making use of structure (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.

• $$5 + 1$$
• $$5 + 2$$
• $$6 + 2$$
• $$7 + 3$$

### Student Response

For access, consult one of our IM Certified Partners.

### Activity Synthesis

• “How is the second expression the same as the first expression? How is it different?” (The first addend is 5, but the second addend adds 1.)
• “How is the sum of the second expression different?” (The sum is 1 more than the first.)

## Activity 1: Write Equations (15 minutes)

### Narrative

The purpose of this activity is for students to write equations that match the story problems. The story problems are written with all three quantities revealed so students can focus on making sense of the problem, determine the operation, and write a matching equation. When students connect the quantities in a story problem to an equation, they reason abstractly and quantitatively (MP2).

Representation: Internalize Comprehension. Synthesis: Invite students to identify which details were the most important to solve the problems. Display the sentence frame, “The next time I solve a story problem, I will pay attention to . . .“
Supports accessibility for: Attention, Conceptual Processing

### Required Materials

Materials to Gather

### Launch

• Groups of 2
• Give students access to 10-frames and connecting cubes or two-color counters.
• Display images of libraries, including any taken of your school or community library.
• “What are some things you can do in a library?”
• 30 seconds: quiet think time
• 1 minutes: partner discussion
• Share and record responses.
• “We are going to work with more stories about the library today.”

### Activity

• “Listen to each story and write an equation to match.”
• 3 minutes: independent work time
• “Share your equations with your partner. Be sure to discuss how each equation matches the story.”
• 3 minutes: partner discussion

### Student Facing

1. 7 people were working on the computers.
3 more people came to the computers.
Now 10 people are working on the computers.

Equation: ________________________________

2. A group of kids was using 10 puppets to act out a story.
They put 5 of the puppets away.
Now they have 5 puppets left.

Equation: ________________________________

3. 5 people came to story time.
Then 4 more people joined.
Now there are 9 people at story time.

Equation: ________________________________

4. 8 students were doing homework at a table.
3 of the students finished their homework and left the table.
Now there are 5 students at the table.

Equation: ________________________________

### Student Response

For access, consult one of our IM Certified Partners.

If students write an equation with an operation that does not match the story, consider asking:

• "How did you decide whether to write an addition or subtraction equation?"
• “How can you act out this story with connecting cubes? What equation matches what you did with the cubes?"

### Activity Synthesis

• Display the equation that matches the first story problem.
• “How does this equation match the story?”
• Repeat for each problem as time allows.
• Explain that none of the numbers in these equations have a box around them because there was no question to answer in these stories.

## Activity 2: Solve and Write Equations (20 minutes)

### Narrative

The purpose of this activity is for students to solve and write equations to match Add To and Take From, Result Unknown story problems. Students make sense of and represent each story problem in a way that makes sense to them (MP1). Students should have access to connecting cubes or two-color counters. They may use objects or drawings to represent and solve the problems. They may use known addition or subtraction facts to solve the problems. Students write an addition or subtraction equation to match each story problem and explain how it matches. Each equation should include a box around the answer to the problem. The most important thing is for students to be able to relate the numbers in the equation to the different parts of the story (MP2).

MLR6 Three Reads. Keep books or devices closed. To launch this activity, display only the first problem stem, without revealing the question. “We are going to read this story problem three times.” After the 1st Read: “Tell your partner what happened in the story.” After the 2nd Read: “What are all the things we can count in this story?” Reveal the question. After the 3rd Read: “What are different ways we can solve this problem?” Repeat with the other three problems.

### Required Materials

Materials to Gather

### Launch

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

### Activity

• "Now you will solve the problems and write equations to match. You can solve the problems in any way that makes sense to you."
• 5 minutes: partner work time
• “Find another group and discuss each problem. Share the equation you wrote and how it matches the story."
• 5 minutes: small-group discussion
• Monitor for students who wrote equations that match the stories and can explain how they match.

### Student Facing

1. There was a stack of 6 books on the table.
Someone put 4 more books in the stack.
How many books are in the stack now?
Show your thinking using drawings, numbers, or words.

Equation: ________________________________

2. 9 books were on a cart.
The librarian took 2 of the books and put them on the shelf.
How many books are still on the cart?
Show your thinking using drawings, numbers, or words.

Equation: ________________________________

3. 2 kids were working on an art project.
7 kids join them.
How many kids are working on the art project now?
Show your thinking using drawings, numbers, or words.

Equation: ________________________________

4. The librarian had 8 bookmarks.
He gave 5 bookmarks to kids at the library.
How many bookmarks does he have now?
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 the equation for each story problem.

## Lesson Synthesis

### Lesson Synthesis

Display the problem about bookmarks and $$8 - 5 = \boxed{\phantom{3}}$$.

“Today we solved story problems and wrote equations to match the problems. We put a box around the answer to the problem in our equation. Look at this problem and this equation. What do you notice? What do you wonder?” (I notice the expression $$8 - 5$$ which is 3. I notice the expression matches the story problem. I see a blank box. I wonder if 3 goes in the blank box.)

If needed, ask “How does this story problem connect to the equation $$8 - 5 = \boxed{\phantom{3}}$$?” ($$8 - 5$$ represents the 8 bookmarks the librarian had and the 5 he gives to the kids. The blank box is where the 3 goes since that is the answer to the question.)

## Cool-down: Books on the Shelf (5 minutes)

### Cool-Down

For access, consult one of our IM Certified Partners.