# Lesson 14

## Warm-up: Number Talk: Multiple Addends (10 minutes)

### Narrative

This Number Talk encourages students to think about place value and to rely on the properties of operations to make it easier to find the value of an expression mentally (MP7). The methods elicited here will be helpful later in the lesson when students make sense of and solve Put Together/Take Apart, Result Unknown problems with multiple two-digit addends.

### Launch

• Display one problem.
• “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.

• $$5 + 9 + 5$$
• $$25 + 9 + 5$$
• $$25 + 15 + 19$$
• $$25 + 30 + 15 + 19$$

### Student Response

For access, consult one of our IM Certified Partners.

### Activity Synthesis

• “How did you choose which numbers to add first?” (I looked for ways to make a ten. I looked for ways to use sums I’ve done before. I added tens first then I tried to make tens with the ones.)

## Activity 1: Put It All Together (15 minutes)

### Narrative

The purpose of this activity is for students to represent and solve a two-step story problem. The story problem is presented in parts, and students are encouraged to represent each part in a way that makes sense to them. In the synthesis, students compare different ways they represent and solve the problem (MP2).

MLR8 Discussion Supports. To support both students with an opportunity to produce language, display a question starter “How did you do the problem?” and sentence frames “First, I _____ because . . . .” “My method is like yours because . . . .” “Our methods are different because . . . .”

### Required Materials

Materials to Gather

• Groups of 2

### Activity

• 5 minutes: independent work time
• 5 minutes: partner discussion
• Monitor for students who use tape diagrams and equations to represent each problem.

### Student Facing

1. Andre gathered seeds. He has 25 sunflower seeds and 17 squash seeds. How many seeds does he have? Show your thinking.

2. Andre gathered more seeds. He has 35 cucumber seeds. How many seeds does Andre have altogether? Show your thinking.

### Student Response

For access, consult one of our IM Certified Partners.

### Activity Synthesis

• Invite previously identified students to share their tape diagram and equation for each part.
• “How did _____ represent the problem? How does each representation show the story problem?”
• Display $$25 + 17 + 35 = {?}$$
• “How does this equation represent Andre’s seeds?” (It shows all the seeds he has in one equation.)
• “What are other ways we could add to find the sum?” (We could add 25 and 35 first. Then add 17. We could add 17 and 35 and then add 25.)

## Activity 2: Select, Solve, and Share (20 minutes)

### Narrative

The purpose of this activity is for students to represent and solve one- and two-step story problems using methods that make the most sense to them. Students each select a problem to solve on their own and share their work with their group. Each group uses the solutions to solve a two-step Put Together, Result Unknown problem. Students have multiple opportunities to describe and compare the different ways their peers represent and solve story problems (MP2, MP3, MP6).

This activity uses MLR7 Compare and Connect. Advances: representing, conversing.

Action and Expression: Internalize Executive Functions. Invite students to plan a strategy, including the tools they will use, to solve the problem. If time allows, invite students to share their plan with a partner before they begin.
Supports accessibility for: Conceptual Processing, Organization, Attention

### Required Materials

Materials to Gather

• Groups of 3

### Activity

• “Read the problems together. Each person in your group must solve one problem on their own. Decide together who will solve each problem. Be ready to share your thinking with your group.”
• “After everyone shares and you agree on how many seeds each character has, complete the story and solve the problem together.”
• 4 minutes: independent work time
• 5 minutes: small-group discussion

### Student Facing

1. Decide which problem each member of your group will solve.

1. Priya has 24 fewer seeds than Tyler. Tyler has 53 seeds. How many seeds does Priya have?
2. Jada and Mai have 61 seeds. Jada has 39 seeds. How many seeds does Mai have?
3. Kiran started the game with 24 seeds. He won 17 seeds on his turn. How many seeds does he have now?
2. Solve the problem. Show your thinking.
3. Share your thinking with your group. After everyone has shared, complete the sentences with your answers. Then solve the story problem together.

• Priya has ____________ seeds.

• Mai has ____________ seeds.

• Kiran has ____________ seeds.

How many seeds do they have in all?

### Student Response

For access, consult one of our IM Certified Partners.

### Activity Synthesis

MLR7 Compare and Connect

• Give each group a piece of chart paper and markers.
• “Create a visual display that shows your thinking about the story problem you solved as a group.  You may want to include details such as drawings, diagrams, equations, and labels to help others understand your thinking.”
• 5–7 minutes: gallery walk
• “What is the same and what is different between the different ways we made sense of and solved the story problem?” (Some groups used more than one tape diagram and equation to represent the problem. Some groups used one equation. We added the characters seeds in different ways. We used different ways to show how we added.)
• 30 seconds quiet think time
• 1 minute: partner discussion

## Lesson Synthesis

### Lesson Synthesis

“In this section, we practiced making sense of and solving different kinds of story problems and using what we know about adding and subtracting two-digit numbers.”

“What do you do to make sense of and solve story problems?”

“What ideas for solving story problems have you learned from others?”

## Cool-down: Jada’s Seeds (5 minutes)

### Cool-Down

For access, consult one of our IM Certified Partners.

## Student Section Summary

### Student Facing

In this section, we solved many different kinds of story problems. We used diagrams and equations to make sense of problems.

Jada started with some seeds. Then she won 28 seeds from Elena. Now she has 65 seeds.
How many seeds did Jada have at the start?

$${?} + 28 = 65$$

We shared how we make sense of story problems, how we solve them, and what we learned from each other.