# Lesson 17

Mosaic Pictures (optional)

## Warm-up: Notice and Wonder: Mosaic (10 minutes)

### Narrative

The purpose of this warm-up is for students to discuss the context of mosaics and the mathematics that might be involved, which will be useful when students create their own mosaics in a later activity. While students may notice and wonder many things about this image, the different smaller shapes used to create the mosaic are the important discussion points.

### Launch

- Groups of 2
- Display the image.
- “What do you notice? What do you wonder?”
- 1 minute: quiet think time

### Activity

- “Discuss your thinking with your partner.”
- 1 minute: partner discussion
- Share and record responses.

### Student Facing

What do you notice? What do you wonder?

### Student Response

Teachers with a valid work email address can click here to register or sign in for free access to Student Response.

### Activity Synthesis

- “A mosaic is a pattern or picture created using small pieces of ceramic, stone, or glass to cover a surface.”
- “Ancient Greek and Roman artists decorated important buildings with mosaics, and Jewish and Muslim artists in the Middle East created mosaics to decorate religious buildings.”
- “The pieces that create a mosaic can be cut in different shapes. What shapes do you notice in this mosaic?”
- “In the next activity, you’ll create your own mosaics with rectangles.”

## Activity 1: Create a Mosaic (40 minutes)

### Narrative

The purpose of this activity is for students to create rectangles from colored paper. Students make identical rectangles that have one side length that is a whole number and one side length that is a fraction greater than 1. Then, as a group they create one mosaic. It is not necessary for students to use all of the rectangle pieces. It is important that all students in each group measure their rectangles using the same unit, either inches or centimeters.

*Action and Expression: Provide Access for Physical Action.*Provide access to pre-cut materials to reduce barriers for students who need support with fine motor skills and students who benefit from extra processing time.

Supports accessibility for: Fine Motor Skills, Organization, Visual-Spatial Processing

### Required Materials

Materials to Gather

### Required Preparation

- Each student needs a few sheets of the same colored paper.
- Each group of 4 needs a ruler, scissors, glue and one large piece of poster paper.

### Launch

- Groups of 4
- Distribute materials. Make sure each student in the group gets a different color paper.

### Activity

- 10 minutes: independent work time
- 5 minutes: group work time
- Monitor for students who:
- write numerical expressions to represent the area of the rectangles.
- use a diagram or write on the physical rectangles.

### Student Facing

- Use the colored paper and scissors to cut identical rectangles. Make sure the measurement of one side of the rectangle is a whole number and the other is a fraction greater than 1.
- What is the area of one of your rectangles? Show your reasoning.
- Use the rectangles from your group to make a group mosaic by arranging some of the different colored rectangles on a blank piece of paper.

### Student Response

Teachers with a valid work email address can click here to register or sign in for free access to Student Response.

### Activity Synthesis

- Invite a few students to share and describe their mosaic.
- “What are some questions we can ask about the mosaics?” (Which color rectangle did we use the most of? What are some other ways we can arrange the same pieces? What are some other pieces that can make the same pattern? How much would this cost if we actually made this using hard materials?)

## Activity 2: Cost of Mosaic (30 minutes)

### Narrative

The purpose of this activity is for students to apply their understanding of multiplying whole numbers by fractions greater than 1 to determine the cost of making a mosaic with different materials. It is not necessary for students to find the exact cost for the mosaic. Encourage students to use estimation strategies. Some students may find the exact cost as a fraction of a dollar, for example \(131\frac{3}{5}\) dollars. Encourage students to make sense of the fraction with respect to money.

This activity uses *MLR1 Stronger and Clearer Each Time*. Advances: Reading, Writing.

### Launch

- Group of 4
- Display table from student task.
- “Traditionally mosaics are made of stone, tile, or glass pieces. Imagine you are making your mosaic as art for the school. In this activity, you will figure out the cost of your mosaic.”

### Activity

- 8-10 minutes: Group work time
- Monitor for students who:
- Determine the cost for each color rectangle needed and then determine the total cost.
- Find the approximate total area of the materials needed for the mosaic and then determine the cost.
- Write clear expressions that show multiplication of whole numbers by fractions greater than 1.

### Student Facing

About how much would it cost to create your mosaic with your preferred material? Explain or show your reasoning.

Material | Cost per square unit |
---|---|

Stone | \$5 |

Tile | \$3 |

Glass | \$2 |

### Student Response

Teachers with a valid work email address can click here to register or sign in for free access to Student Response.

### Activity Synthesis

**MLR1 Stronger and Clearer Each Time**

- “Share your response with a partner. Take turns being the speaker and the listener. If you are the speaker, share your ideas and writing so far. If you are the listener, ask questions and give feedback to help your partner improve their work.”
- 3–5 minutes: structured partner discussion.
- Repeat with 2–3 different partners.
- If needed, display question starters and prompts for feedback.
- “Can you add an expression to show . . .?”
- “The part I understood best was . . .”
- “I liked how you . . .”

- “Revise your initial draft based on the feedback you got from your partners.”
- 2–3 minutes: independent work time

## Lesson Synthesis

### Lesson Synthesis

“Today we made mosaics with rectangles. Why is it important for an artist to know the area of the pieces they use for the mosaic?” (It affects how much the mosaic will cost. They need to know if their pieces will fit in the space they have.)

“In this lesson, many of us multiplied whole numbers by fractions greater than 1. Explain to a partner, what strategies you have to multiply whole numbers by fractions.”