standard_description: Use similar triangles to explain why the slope m is the same between any two distinct points on a non-vertical line in the coordinate plane; derive the equation y = mx for a line through the origin and the equation y = mx + b for a line intercepting the vertical axis at b.
problem_activity: Narrative
The purpose of this warm-up is for students to consider concepts of number in a familiar context. Students compare groups of images in the synthesis. Adjust the context to better reflect students’ interests and experiences as needed. For example, the question can be adjusted to ask students to choose between two types of playground equipment that are available at school or in the community where students live. A question can also be chosen from the list that students generated in a previous lesson.
Required Materials
Materials to Copy
Questions About Us Chart
Launch
Groups of 2
Display the Questions About Us Chart.
“Would you rather play on the slide or on the swings?”
30 seconds: quiet think time
Record each student’s choice with a circle in a 5-frame.
Activity
“How can we figure out how many students would rather play on the slide?”
30 seconds: quiet think time
30 seconds: partner discussion
Share responses.
Demonstrate or invite students to demonstrate counting.
“How many students would rather play on the slide?”
If needed, ask, “How can we figure out how many students would rather play on the swings?”
30 seconds: quiet think time
30 seconds: partner discussion
Share responses.
Demonstrate or invite students to demonstrate counting.
“How many students would rather play on the swings?”
Student Response
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Activity Synthesis
“Did fewer people choose the swings or the slide? How do you know?”


aligns: no