standard_description: Prove the slope criteria for parallel and perpendicular lines and use them to solve geometric problems (e.g., find the equation of a line parallel or perpendicular to a given line that passes through a given point).
problem_activity: Narrative
The purpose of this activity is for students to make groups with more or fewer objects than a given group of objects. When asking students to make a group that has more objects than the given group, the given group will have very few objects. Similarly, when asking them to make a group that has fewer objects than the given group, the given group will have many objects. This should allow students to create and compare the groups visually. In a future lesson, students will create groups with more or fewer objects than a given group when the quantities are closer, where it will be helpful for students to match or count the objects in each group.
Required Materials
Materials to Gather
Counters
Materials from a previous activity
Required Preparation
Each group of 2 needs a bag of green triangle and orange square pattern blocks from the previous activity.
Launch
Groups of 2
Give each group of students a bag of 8–10 green triangle pattern blocks and a bag of 1–3 orange square pattern blocks.
Activity
“Make a group with counters that has more than the group of orange squares.”
30 seconds: quiet think time
1 minute: partner work time
“Figure out and tell your partner how many counters you have. Then figure out and tell your partner how many orange squares you have.”
2 minutes: partner work time
“Make a group with counters that has fewer than the group of green triangles.”
30 seconds: quiet think time
1 minute: partner work time
“Figure out and tell your partner how many counters you have. Then figure out and tell your partner how many green triangles you have.”
2 minutes: partner work time
Activity Synthesis
Invite 2–3 students to share the groups of counters that they made that have fewer than the green triangles.
“What is the same about the groups they made? What is different?” (They all made groups with different numbers of counters. They all have fewer than the green triangles.)


aligns: no