The purpose of this Warm-up is to invite students to share what they know and how they can represent division. This is the first time students experience the What Do You Know about _____? routine in IM Grade 3. Students should be familiar with this routine from a previous grade. However, they may benefit from a brief review of the steps involved.
Launch
Display the word "division."
“What do you know about division?”
1 minute: quiet think time
Activity
Record responses.
“How could we represent division?” (with a drawing or diagram, with connecting cubes, with an equation or expression)
Student Task Statement
What do you know about division?
Student Response
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Advancing Student Thinking
Activity Synthesis
“We have already learned a lot about division. We are going to continue to learn about division by working with greater numbers than we have before.”
Consider asking: “What connections do you see between different answers?”
Activity 1
20 mins
Groups on a Field Trip
Standards Alignment
Building On
Addressing
3.OA.3
Use multiplication and division within 100 to solve word problems in situations involving equal groups, arrays, and measurement quantities, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.
The purpose of this 5 Practices activity is to elicit students’ existing approaches for finding the value of quotients with greater numbers and encourage them to think about ways to multiply and divide in smaller parts. Students should be encouraged to use whatever approach makes sense to them.
Monitor for and select students with the following approaches to share in the Activity Synthesis:
Make groups of 4 with objects, drawings, arrays, or base-ten blocks. Add groups of 4 until they reach 48, and count to see how many groups they make.
Multiply up starting with .
Decompose the dividend into tens and ones and divide each part (using drawings or known facts).
The approaches are sequenced from more concrete to more abstract to help all students make sense of ways to find the quotient by multiplying or dividing in parts, especially by using what they know about place value. Aim to elicit both key mathematical ideas and a variety of student voices, especially students who haven't shared recently. If appropriate, discuss connections between the approaches as they are shared, rather than after all selected students have shared. It is not essential that all the listed approaches are discussed, as students will consider these ideas in upcoming lessons. The main goal here is to elicit what students currently understand, and to make connections to thinking about multiplying and dividing in parts if it comes up.
When students make sense of the contextual division problem, they reason abstractly and quantitatively (MP2). Students who use the relationship between multiplication and division make use of structure (MP7).
MLR7 Compare and Connect. Synthesis: Invite students to prepare a visual display that shows the approach they used to figure out the number of groups. Encourage students to include details that will help others interpret their thinking. For example, specific language, using different colors, shading, arrows, labels, notes, diagrams, or drawings. Give students time to investigate each other’s work. During the whole-class discussion, ask students, “Did anyone solve the problem the same way, but would explain it differently? How did the groups of 4 show up in each method? Why did the different approaches lead to the same outcome?” Advances: Representing, Conversing
Representation: Access for Perception. Synthesis: As students identify correspondences between approaches, follow along and point to the relevant parts of each approach to amplify student thinking and illustrate connections. Supports accessibility for: Conceptual Processing, Visual-Spatial Processing
Launch
Display the statement: “On a field trip to the aquarium, a class of students is splitting into groups.”
“What do you notice? What do you wonder?” (They are going to the aquarium in groups. They can’t go in one big group. How many kids are in the class? How many kids are in each group? Are the groups the same size?)
1 minute: quiet think time
Share and record responses.
Give students access to connecting cubes or counters, base-ten blocks, and grid paper.
Activity
“Solve this problem. Use whatever strategy or representation that works best for you.”
5 minutes: independent work time
As you monitor for the approaches listed in the Activity Narrative, consider asking:
“Where are the groups of 4 in your work?”
“Where is the number of groups in your work?”
“How did you start? Did you change your approach while you were working?”
“Share your answer and the way you found it with your partner. Talk about how the ways are alike and how they are different.”
3 minutes: partner discussion
Student Task Statement
There are 48 students going on a field trip to the aquarium. They visit the exhibits in groups of 4 students. How many groups will there be?
Show your thinking using diagrams, symbols, or other representations.
Student Response
Activity Synthesis
Invite previously selected students to share in the given order. Record or display their work for all to see.
As each approach is presented, invite the class to ask questions.
Keep all the approaches displayed.
Connect students’ approaches by asking:
“How are these ways of solving the problem alike?” (All the approaches used to help break the problem into smaller parts. The approaches with division and multiplication equations both had .)
“How are they different?” (In some, students drew a representation. In others, students wrote multiplication or division expressions or equations.)
If some approaches show breaking the problem into smaller parts, connect students’ approaches to the learning goal by asking:
“How did _____ think about breaking the problem into smaller parts? Why was that approach helpful for this problem?” (They thought about multiplying by 10 first because they know , and that's close to the total. It helped because they didn't have to add or skip-count by 4 as many times or draw as many things.)
Activity 2
15 mins
Bus Ride and Lunch Groups
Standards Alignment
Building On
Addressing
3.OA.3
Use multiplication and division within 100 to solve word problems in situations involving equal groups, arrays, and measurement quantities, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.
The purpose of this activity is for students to consider their strategies as they solve two other division problems involving equal groups with greater numbers. The divisor in the first problem is a low one-digit number. Students can see from the given situation that it is the number of groups. In the second problem, the divisor is a teen number, and the context suggests that it is the size of one group. Students are likely to adjust their strategy based on these observations. Focus the discussion on how students may have reasoned differently given a greater divisor or given what they understand about the situation.
Launch
Groups of 2
“Read the two problems about another field trip. Think about what strategies you might use to solve them.”
1 minute: quiet think time
“Share your thinking with your partner.”
1 minute: partner discussion
Give students access to connecting cubes or counters, base-ten blocks, and grid paper.
Activity
“Work independently on the problems for a few minutes. Then share your responses with your partner.”
5 minutes: independent work time
3 minutes: partner discussion
Monitor for students who use different representations (drew different diagrams or wrote different types of expressions or equations) for the two problems.
Student Task Statement
For each question, show your thinking using diagrams, symbols, or other representations.
On another field trip, 72 students and teachers rode in 3 buses to a science museum. The same number of people rode in each bus. How many people rode in each bus?
During lunch, the 72 people sat at long tables. There were 12 people at each table. How many tables did they use?
Student Response
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Activity Synthesis
Invite students to share their responses. Display or record their reasoning.
Poll the class on whether they used a different strategy for solving the second problem than they used for the first.
Ask those who used a different strategy. “Why did you change your strategy?” (In the first problem, the 3 represents 3 groups. In the second problem, the 12 is how many in each group. In the first, the number used to divide is smaller. In the second, the number is larger.)
Lesson Synthesis
“Today we found the value of quotients with greater numbers than we have worked with before.”
“We saw problems that involved dividing 48 by 4, 72 by 3, and 72 by 12.”
“Reflect on the strategies you used. Did the size of the number being divided—48 and 72—affect how you solved the problem? If so, how?” (When the number was larger, I broke it up into more parts. When the number was smaller, I used a drawing, but when it was larger, I used another way.)
Have feedback on the curriculum?
Help us improve by sharing suggestions or reporting issues.
Interpret whole-number quotients of whole numbers, e.g., interpret 56 ÷ 8 as the number of objects in each share when 56 objects are partitioned equally into 8 shares, or as a number of shares when 56 objects are partitioned into equal shares of 8 objects each. For example, describe a context in which a number of shares or a number of groups can be expressed as 56 ÷ 8.