This Warm-up prompts students to compare four expressions. 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 expressions for all to see. Give students 1 minute of quiet think time and ask them to indicate when they have noticed three expressions that go together and can explain why. Next, tell students to share their response with their group, and then together to find as many sets of three as they can.
Which three go together? Why do they go together?
A
45+5+5+5
B
410+6+4
C
410+8+6+4
D
57+6+4+2+1
Sample responses:
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. Because there is no single correct answer to the question of which three go together, attend to students’ explanations and ensure that the reasons given are correct.
During the discussion, prompt students to explain the meaning of any terminology that they use, such as “numerator,” “denominator,” “mean,” or “sum,“ and to clarify their reasoning as needed. Consider asking:
If it is not mentioned, bring up that options A, C, and D can go together because they could be used to calculate a mean.
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This Warm-up prompts students to compare four expressions. 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 expressions for all to see. Give students 1 minute of quiet think time and ask them to indicate when they have noticed three expressions that go together and can explain why. Next, tell students to share their response with their group, and then together to find as many sets of three as they can.
Which three go together? Why do they go together?
A
45+5+5+5
B
410+6+4
C
410+8+6+4
D
57+6+4+2+1
Sample responses:
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. Because there is no single correct answer to the question of which three go together, attend to students’ explanations and ensure that the reasons given are correct.
During the discussion, prompt students to explain the meaning of any terminology that they use, such as “numerator,” “denominator,” “mean,” or “sum,“ and to clarify their reasoning as needed. Consider asking:
If it is not mentioned, bring up that options A, C, and D can go together because they could be used to calculate a mean.