# Lesson 14

Hundreds of Objects (optional)

## Warm-up: Notice and Wonder: Jar of Beans (10 minutes)

### Narrative

This warm-up prompts students to make sense of a problem before solving it, by familiarizing themselves with a context and the mathematics that might be involved. In the next activity, students will see three different ways the amount of beans in a cup are counted.

### 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?

### Student Response

For access, consult one of our IM Certified Partners.

### Activity Synthesis

• “Can you imagine counting out so many beans? How would you do it?”
• “We are going to keep thinking about those counting ideas in our first activity today.”

## Activity 1: Cup of Beans (10 minutes)

### Narrative

The purpose of this activity is for students to compare methods that can be used to count numbers between 100 and 999. Students see images of beans that are put in groups of 5 and another in groups of 10. A third image uses groups of 100, groups of 10, and single beans. Students make connections to place value and their understanding of the base-ten structure (MP2, MP7). They also consider opportunities for accuracy and efficiency when they articulate pros and cons for each method.

### Launch

• Groups of 2
• Display image of a cup of beans or display a cup of beans.

### Activity

• 1 minute: quiet think time
• 5 minutes: small-group discussion
• Monitor for students who:
• describe the organization and group sizes in each method
• describe Clare’s method in terms of hundreds, tens, and ones
• discuss ideas such as efficiency (how long it takes) and accuracy (chances of mistakes)

### Student Facing

Clare, Noah, and Jada counted a cup of dried beans. They each came up with 529 beans. The following pictures show how each of them counted.

Noah’s counting strategy:

Clare’s counting strategy:

1. What do you notice about each of their strategies?

3. What is challenging about each strategy?

### Student Response

For access, consult one of our IM Certified Partners.

### Activity Synthesis

• Invite previously selected students to share their observations.
• “Which of these strategies do you believe would be the fastest or slowest? Explain.”
• “Do you think it would be easier to make a mistake using one of these strategies? Which one and why?”
• “Which strategy do you prefer? Why?”

## Activity 2: Lots of Beans (25 minutes)

### Narrative

The purpose of this activity for students to choose their own method to count between 100 and 999 objects accurately and efficiently. Students should be encouraged to use their understanding of place value.

Representation: Internalize Comprehension. Provide students with a graphic organizer, such as a sorting mat with various circles to organize the groups of beans and record how many beans are in each group.
Supports accessibility for: Organization, Memory
MLR7 Compare and Connect. Synthesis: After the Gallery Walk, lead a discussion comparing, contrasting, and connecting the different strategies used to count. To amplify student language, and illustrate connections, follow along and point to the relevant parts of the displays as students speak.

### Required Materials

Materials to Gather

### Required Preparation

• Each group of 2 to 4 students will need between one-half cup to one cup of beans or other small objects to count. If real-world objects are unavailable, centimeter cubes could be used instead.

### Launch

• Groups of 2 or 4.
• Give students each group $$\frac{1}{2}$$ to 1 cup of beans and a sticky note.
• “You will use any method you prefer to count the beans and then write your result on one sticky note and then fold it to hide your result.”

### Activity

• 510 minutes: small-group work time
• Monitor for students who make groups of 5, groups of 10, or groups of 100.
• Display and read the gallery walk questions.
• “Think about these questions as you walk around.”
• 10 minutes: gallery walk

### Student Facing

Organize and count your beans. Use the space to record your thinking.

Gallery walk questions:

• How can this be made clearer?
• How is this strategy the same as your strategy? How is it different?
• Does your group have more or fewer beans? Explain your reasoning.

### Student Response

For access, consult one of our IM Certified Partners.

If students double count beans or groups of beans ask, “How can you organize your piles to make sure you did not double count some of the piles?”

### Activity Synthesis

• “When you organized your beans and counted them, did you feel confident about your results? Why?”
• Invite students to share answers to the gallery walk questions.

## Lesson Synthesis

### Lesson Synthesis

“Today, we used strategies we have been studying about numbers between 100 and 999 to count a large amount of beans.”

“What are important things to remember when you count a large number of objects? What is important when you represent your strategy so that it is clear to others?”