This is the first Math Talk activity in the course. See the launch for extended instructions for facilitating this activity successfully.
This Math Talk focuses on multiplying a whole number by a unit fraction. It encourages students to think about the relationship between multiplication and division and to rely on properties of operations to mentally solve problems. The strategies elicited here will be helpful later in the lesson when students are identifying scale factors.
This is the first time students do the Math Talk instructional routine in this course, so it is important to explain how it works before starting.
Explain that a Math Talk has four problems, revealed one at a time. For each problem, students have a minute to quietly think and are to give a signal when they have an answer and a strategy. The teacher then selects students to share different strategies (likely 2–3, given limited time), and might ask questions such as “Who thought about it in a different way?” The teacher then records the responses for all to see, and might ask clarifying questions about the strategies before revealing the next problem.
Consider establishing a small, discreet hand signal that students can display when they have an answer they can support with reasoning. This signal could be a thumbs-up, a certain number of fingers that tells the number of responses they have, or another subtle signal. This is a quick way to see if the students have had enough time to think about the problem. It also keeps students from being distracted or rushed by hands being raised around the class.
Tell students to close their books or devices (or to keep them closed). Reveal one problem at a time. For each problem:
Find the value of each expression mentally.
Make sure the connection to division is brought up in the discussion, before moving on to the second expression.
To involve more students in the conversation, consider asking:
The key takeaway is that these problems all involve multiplying by a unit fraction. One strategy that works in such cases is dividing the other factor by the denominator of the fraction.
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This is the first Math Talk activity in the course. See the launch for extended instructions for facilitating this activity successfully.
This Math Talk focuses on multiplying a whole number by a unit fraction. It encourages students to think about the relationship between multiplication and division and to rely on properties of operations to mentally solve problems. The strategies elicited here will be helpful later in the lesson when students are identifying scale factors.
This is the first time students do the Math Talk instructional routine in this course, so it is important to explain how it works before starting.
Explain that a Math Talk has four problems, revealed one at a time. For each problem, students have a minute to quietly think and are to give a signal when they have an answer and a strategy. The teacher then selects students to share different strategies (likely 2–3, given limited time), and might ask questions such as “Who thought about it in a different way?” The teacher then records the responses for all to see, and might ask clarifying questions about the strategies before revealing the next problem.
Consider establishing a small, discreet hand signal that students can display when they have an answer they can support with reasoning. This signal could be a thumbs-up, a certain number of fingers that tells the number of responses they have, or another subtle signal. This is a quick way to see if the students have had enough time to think about the problem. It also keeps students from being distracted or rushed by hands being raised around the class.
Tell students to close their books or devices (or to keep them closed). Reveal one problem at a time. For each problem:
Find the value of each expression mentally.
Make sure the connection to division is brought up in the discussion, before moving on to the second expression.
To involve more students in the conversation, consider asking:
The key takeaway is that these problems all involve multiplying by a unit fraction. One strategy that works in such cases is dividing the other factor by the denominator of the fraction.