This Warm-up prompts students to compare four equations. It gives students a reason to use language precisely (MP6). It gives the teacher an opportunity to hear how students use terminology and talk about characteristics of the items in comparison to one another.
Arrange students in groups of 2–4. Display the equations for all to see. Give students 1 minute of quiet think time, and ask them to indicate when they have noticed three images that go together and can explain why. Next, tell students to share their response with their group and then together find as many sets of three as they can.
Which three go together? Why do they go together?
A
21x=-50
B
x+90=-100
C
-60t=30
D
-0.01=-0.001x
Sample responses:
A, B, and C go together because:
A, B, and D go together because:
A, C, and D go together because:
B, C, and D go together because:
Invite each group to share one reason why a particular set of three go together. Record and display the responses for all to see. After each response, ask the class if they agree or disagree. Since there is no single correct answer to the question of which three go together, attend to students’ explanations, and ensure the reasons given are correct.
During the discussion, prompt students to explain the meaning of any terminology they use, such as “positive,” “negative,” “addition,” and “subtraction,” and to clarify their reasoning as needed. Consider asking:
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This Warm-up prompts students to compare four equations. It gives students a reason to use language precisely (MP6). It gives the teacher an opportunity to hear how students use terminology and talk about characteristics of the items in comparison to one another.
Arrange students in groups of 2–4. Display the equations for all to see. Give students 1 minute of quiet think time, and ask them to indicate when they have noticed three images that go together and can explain why. Next, tell students to share their response with their group and then together find as many sets of three as they can.
Which three go together? Why do they go together?
A
21x=-50
B
x+90=-100
C
-60t=30
D
-0.01=-0.001x
Sample responses:
A, B, and C go together because:
A, B, and D go together because:
A, C, and D go together because:
B, C, and D go together because:
Invite each group to share one reason why a particular set of three go together. Record and display the responses for all to see. After each response, ask the class if they agree or disagree. Since there is no single correct answer to the question of which three go together, attend to students’ explanations, and ensure the reasons given are correct.
During the discussion, prompt students to explain the meaning of any terminology they use, such as “positive,” “negative,” “addition,” and “subtraction,” and to clarify their reasoning as needed. Consider asking: