# Lesson 7

Different Square Units (Part 2)

## Warm-up: Notice and Wonder: A Bigger Square (10 minutes)

### Narrative

The purpose of this warm-up is to elicit the idea that larger square units, specifically the square meter, can be useful in situations involving large areas. While students may notice and wonder many things about the image, the idea of tiling a large area with larger square units is the important discussion point.

### 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?

### Activity Synthesis

• If needed, “What could you measure with this square?” (You could measure the area of big areas, like the playground.)
• “Why might you want this square instead of square centimeters or square inches?” (It takes fewer squares of this size to measure an area that is a lot larger like a playground or a room.)

## Activity 1: Square Feet and Square Meters (10 minutes)

### Narrative

The purpose of this activity is for students to encounter larger squares units, specifically the square meter and the square foot. There are two options for introducing square meters and square feet for the first time. Students get a sense of the size of a square meter and a square foot from the images in the activity. Also, you could construct and display a square foot and a square meter using rubber bands, 4 meter sticks, and 4 rulers.

### Required Preparation

• Optional: Create square foot and square meter units made from rulers, meter sticks, and rubber bands.

### Launch

• Groups of 2
• Display a square meter.
• “This is a square meter because it has a side length of 1 meter. Think about what kinds of areas would make sense to measure with square meters.”
• 1 minute: quiet think time

### Activity

• 1–2 minutes: partner discussion
• Share and record responses.
• Display a square foot.
• “This is a square foot because it has a side length of 1 foot. Think about what kinds of areas would make sense to measure with square feet.”
• 1 minute: quiet think time
• 1–2 minutes: partner discussion
• Share and record responses.

### Student Facing

1. This is a square meter.

What kinds of areas would make sense to measure with square meters? Be ready to explain your reasoning.

2. This is a square foot.

What kinds of areas would make sense to measure with square feet? Be ready to explain your reasoning.

### Activity Synthesis

• Display examples of each square unit used so far (square centimeter, square inch, square foot, and square meter).
• “How are the square units that we’ve learned about in this activity different from square inches and square centimeters?” (They cover more space. They could be used to measure larger areas.)

## Activity 2: Which Square Unit? (15 minutes)

### Narrative

The purpose of this activity is for students to consider the units to use to measure given areas. Students choose from square inches, square centimeters, square feet, and square meters. Students have not spent much time with these square units, so examples should be displayed during this activity to support them in choosing the unit that makes the most sense in the given situation.

MLR8 Discussion Supports. Before partner work time, remind students to use words and phrases such as area, square centimeters, square inches, square feet, and square meters.
Engagement: Provide Access by Recruiting Interest. Synthesis: Invite students to generate a list of additional examples that connect to their personal backgrounds and interests of items to measure with square inches, square centimeters, square feet, and square meters.
Supports accessibility for: Organization

### Required Materials

Materials to Gather

### Required Preparation

• Gather examples of a square centimeter and a square inch from a previous lesson, and examples of a square meter and a square foot from the previous activity.

### Launch

• Groups of 2
• Display examples of each square unit (square centimeter, square inch, square foot, and square meter).
• “Today we are going to choose some square units that we would use to measure some areas that we might find around a school. What are some areas that you might measure around your home or community?”
• 1 minute: quiet think time
• Share responses.

### Activity

• “Discuss the first problem with your partner.”
• 4–5 minutes: partner work time
• Whole-class discussion.
• “Now complete the next problem to choose the area that best matches each item.”
• 1 minute: independent work time
• 5 minutes: partner work time

### Student Facing

1. For each area tell if you would use square centimeters, square inches, square feet, or square meters to measure it and why you chose that unit.

1. The area of a baseball field

2. The area of a cover of a book you’re reading

3. The area of our classroom

4. The area of a piece of paper

5. The area of the top of a table

6. The area of the screen on a phone

2. Choose the area that best matches each item. Be ready to explain your reasoning.

1. A playing card

2. The floor of a classroom

3. A sticky note

4. The top of a student desk

### Student Response

If students choose a square unit that isn’t reasonable to use for the given area, consider asking:

• “Tell me how you thought about which square units you would use to measure this area.”
• “How would it affect the measurement if you used a smaller (or larger) square unit?”

### Activity Synthesis

• “How did you think about the area of each item?” (We thought about the size of the area we were measuring to decide which unit made sense. Then we thought about one unit, like one square foot, and then thought about what 3 square feet would be like.)
• “Is it reasonable to think this many of these unit squares could fit in this area?”
• “Why would this make sense with the given area?”
• “How are you imagining the units fitting in this area?”

## Activity 3: Area Scavenger Hunt [OPTIONAL] (10 minutes)

### Narrative

The purpose of this activity is for students to find things they could measure with the standard area units they have learned about. This activity can be completed in the classroom, but could also be completed during a walk around the school or community if time allows. This activity is optional because it could be condensed into a discussion about areas with which students are familiar and what units they would use to measure them. If time doesn't allow for taking a walk around the school or community, this activity could also be completed at a time when students are already walking around the school.

When students recognize the mathematical features of familiar real world objects and use those features to solve problems, they model with mathematics (MP4).

### Launch

• Groups of 2
• Display examples of square centimeters, square inches, square feet, and square meters.
• “We’re going to walk around the classroom (or school, or community) and look for areas that we could measure with the different square units we’ve learned about.”

### Activity

• “List the things you find and the square unit you would use to measure the area in the table. Be sure to include your reasoning for why you chose that unit.”
• 5–7 minutes: partner work time
• Monitor for students who use different units to measure the same area.

### Student Facing

Find some object or space that you would measure with square inches, square centimeters, square feet, and square meters.

area square unit and reasoning
Example: a piece of paper Example: “I think it can fit about 8 inches across and 10 inches down, so square inches work well. It can be measured in square centimeters, too, but would just take a lot more squares. Square feet and square meters would be too large.”

### Activity Synthesis

• Select students to share responses for 3–5 things they saw around the classroom (or school).
• For each object or space that students present, ask if others also chose that object or space and if they chose the same square unit: “Could other square units be used to measure its area?”
• “How did you decide which square unit to use to measure each area?” (I thought about whether the area was a smaller area or a larger area. I chose small units for smaller areas and larger units for larger areas. I thought about how carefully I would want to measure the area.)

## Lesson Synthesis

### Lesson Synthesis

Display examples of each square unit (square centimeter, square inch, square foot, and square meter).

“Now, we’ve worked with different types of square units. Why is it important to have many different options rather than just square centimeters and square inches?” (Square inches and centimeters are too small for measuring larger areas. It would take too many square centimeters to tile a field.)