standard_description: Verify experimentally the properties of dilations given by a center and a scale factor:
- A dilation takes a line not passing through the center of the dilation to a parallel line, and leaves a line passing through the center unchanged.
- The dilation of a line segment is longer or shorter in the ratio given by the scale factor.
problem_activity: Narrative
The purpose of this activity is for students to facilitate the Notice and Wonder they created in the previous activity. Each group takes turns facilitating their Notice and Wonder for another group (or two groups, if time permits).
MLR8 Discussion Supports.
During group work, invite students to take turns sharing their responses. Ask students to restate what they heard using precise mathematical language and their own words. Display the sentence frame: “I heard you say . . .” Original speakers can agree or clarify for their partner.
Advances: Listening, Speaking
Required Materials
Materials to Gather
Chart paper
Markers
Required Preparation
Each group of 3-4 from the previous activity needs 1 piece of chart paper and a marker.
Launch
Groups of 3–4 from the previous activity
Give each group a piece of chart paper and a marker to record responses.
“Now, work with another group and take turns facilitating the Notice and Wonder activity you created.”
Activity
10–12 minutes: small–group work time
Remind groups to switch roles after 5–6 minutes.
Student Facing
Display your image for your classmates.
Ask them, “What do you notice? What do you wonder?”
Give them a minute to discuss together.
Ask them to share what they notice and wonder.
Record their ideas.
Student Response
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Activity Synthesis
“What did you learn as you facilitated your Notice and Wonder?” (Others might notice or wonder things we did not think of. Recording the ideas helps people understand what is being shared.)


aligns: no