This Warm-up prompts students to compare four expressions. In making comparisons, students have a reason to use language precisely (MP6). The activity also enables the teacher to hear the terminology that students know and how they talk about bases and exponents.
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
24
B
42
C
44−240
D
44
Sample responses:
A, B, and C 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 that the reasons given are correct.
During the discussion, prompt students to explain the meaning of any terminology that they use, such as “power” or “exponent,” and to clarify their reasoning as needed. For example, a student may say that A, B, and C all equal 16. Ask how they know this is the case.
If not mentioned by students, tell them that the base (of an exponent) tells what factor to multiply repeatedly. If necessary, remind students that the exponent tells how many factors to multiply. For example, in 24, the base is 2 and the exponent is 4, which means that there are 4 factors of 2 being multiplied together. So 24=2⋅2⋅2⋅2=16.
All skills for this lesson
No KCs tagged for this lesson
This Warm-up prompts students to compare four expressions. In making comparisons, students have a reason to use language precisely (MP6). The activity also enables the teacher to hear the terminology that students know and how they talk about bases and exponents.
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
24
B
42
C
44−240
D
44
Sample responses:
A, B, and C 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 that the reasons given are correct.
During the discussion, prompt students to explain the meaning of any terminology that they use, such as “power” or “exponent,” and to clarify their reasoning as needed. For example, a student may say that A, B, and C all equal 16. Ask how they know this is the case.
If not mentioned by students, tell them that the base (of an exponent) tells what factor to multiply repeatedly. If necessary, remind students that the exponent tells how many factors to multiply. For example, in 24, the base is 2 and the exponent is 4, which means that there are 4 factors of 2 being multiplied together. So 24=2⋅2⋅2⋅2=16.