The purpose of this How Many Do You See? is for students to use grouping strategies to describe the images they see.
In the Activity Synthesis, students describe how two images can be used to describe a multiplicative comparison, and then connect the images to a multiplication equation.
Launch
Groups of 2
“How many do you see, and how do you see them?”
Flash the image.
30 seconds: quiet think time
Activity
Display the image.
“Discuss your thinking with your partner.”
1 minute: partner discussion
Record responses. Use multiplication equations when appropriate.
Repeat for each image.
How many do you see? How do you see them?
Student Response
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Advancing Student Thinking
Activity Synthesis
“How does this show that the second rectangle has 2 times as many as the first rectangle?”
“How could we write an equation that shows this comparison?” ( or or )
Activity 1
Standards Alignment
Building On
Addressing
4.OA.A.1
Interpret a multiplication equation as a comparison, e.g., interpret as a statement that 35 is 5 times as many as 7 and 7 times as many as 5. Represent verbal statements of multiplicative comparisons as multiplication equations.
The purpose of this activity is for students to analyze and describe how images and diagrams can show “ times as many.” Students generate ideas for how to use a multiplication equation to represent the comparison.
Students begin by interpreting an image in which the multiplier (3) and the numbers are given. They explain how some number of times of the lesser amount can be seen in the greater amount. Next they create their own diagram and see different ways of representing the iterations (groups of) the lesser amount to create the greater amount.
During the activity, make connecting cubes accessible for students who may choose to use them for problem solving—either to reason about the quantities or to explain their reasoning.
Launch
Groups of 2
Give students access to connecting cubes.
Display the image of Mai's cubes and Kiran's cubes.
“How do these cubes represent 3 times as many?” (Mai has 6 cubes and Kiran has 2. Mai has 3 groups of 2 cubes. Mai has 6 cubes and Kiran has 2 cubes. Three times as many as 2 is 6, or 3 times 2 is 6.)
Give students access to cubes.
Read the statement about Jada's and Kiran’s cubes as a class.
1 minute: quiet think time
Activity
MLR7 Compare and Connect
“Create a display that shows your thinking about the cubes in each problem and include details to help others understand your thinking.”
6–8 minutes: independent or group work
3 minutes: Gallery Walk
“How does each representation show ‘times as many’?”
30 seconds quiet think time
1 minute: partner discussion
Monitor for students who create diagrams that are similar to connecting-cube images and discrete tape diagrams to share in the Activity Synthesis.
Jada has 4 times as many cubes as Kiran. Draw a diagram to represent the situation.
Diego has 5 times as many cubes as Kiran. Draw a diagram to represent the situation.
Lin has 6 times as many cubes as Kiran. How many cubes does Lin have? Explain or show your reasoning.
Student Response
Activity Synthesis
Invite selected students to share diagrams and explain how they show “times as many.”
If needed, use cubes to represent statements.
“How could you write an equation to compare Kiran’s and Jada’s cubes?”
“What do the numbers in the equation represent in the situation?” (4 is the “4 times as many.” 2 is how many Kiran had. 8 is how many Jada had.)
Write equations for each situation, and ask about what students notice about the relationships.
Activity 2
Standards Alignment
Building On
Addressing
4.OA.A.1
Interpret a multiplication equation as a comparison, e.g., interpret as a statement that 35 is 5 times as many as 7 and 7 times as many as 5. Represent verbal statements of multiplicative comparisons as multiplication equations.
The purpose of this activity is for students to deepen their understanding of how diagrams and multiplication equations can represent “ times as many.” Students explain how the diagrams and equations represent the situation. In order to match situations, diagrams, and equations, students reason abstractly and quantitatively (MP2).
MLR8 Discussion Supports. Students should take turns finding a match and explaining their reasoning to their partner. Display the following sentence frames for all to see: “I noticed _____, so I matched . . . .” Encourage students to challenge each other when they disagree. Advances: Conversing, Representing, Speaking
Engagement: Provide Access by Recruiting Interest. Synthesis: Optimize meaning and value. Invite students to look and listen for examples of multiplicative comparison in their own lives. Encourage them to share these throughout the unit. Supports accessibility for: Conceptual, Processing, Language, Attention
Launch
Groups of 2
“Take turns reading a description, and finding a diagram and an equation that also represent the situation. Explain your reasoning to your partner.”
Activity
5–7 minutes: partner work time
Monitor for students who connect the factors and the product of the equation to the situation and the diagram.
If students finish early, give them blank index cards. Ask them to make several sets of matching representations, shuffle the cards, and trade them with another group that is also creating their own representations.
Here are 4 sets of descriptions, diagrams, and equations that compare pairs of quantities.
Match each description to a diagram and an equation that represent the same situation.
A
Lin has 3 cubes.
Jada has 2 times as many.
B
Han has 3 cubes.
Elena has 3 times as many.
C
D
Priya had 5 cubes.
Noah had 3 times as many.
E
F
G
H
I
J
Mai has 4 cubes.
Diego has 4 times as many.
K
L
Record your matches here:
Set 1: _____, _____, _____
Set 2: _____, _____, _____
Set 3: _____, _____, _____
Set 4: _____, _____, _____
Activity Synthesis
Select students to share their matches.
Record students’ explanations to show how they connected the diagrams and the equations (display or draw the diagrams and the equations, and annotate).
Lesson Synthesis
“Today we looked at a new way to use multiplication equations. Multiplication equations can describe equal groups, but they also represent multiplicative comparison.”
Display a student's representation of Kiran's cubes and Jada's cubes from the first activity.
“Explain how you see in this diagram.” (There are 4 groups of 2 cubes each or Jada has 4 times as many as Kiran does.)
“In this case, the value of the product is 8. How is one of the factors being compared to 8 in this diagram?”
If not mentioned by students, highlight that:
“In the first case, the multiplication equation represents equal groups of objects.”
“In the second case, the multiplication equation represents multiplicative comparison. It allows us to see how many times the number of objects one person has compared to another person.”
Standards Alignment
Building On
Addressing
4.OA.A.1
Interpret a multiplication equation as a comparison, e.g., interpret as a statement that 35 is 5 times as many as 7 and 7 times as many as 5. Represent verbal statements of multiplicative comparisons as multiplication equations.
If students compare additively instead of multiplicatively when using cubes or drawing diagrams, consider asking:
“How would you use the cubes to show 2 more than Kiran's cubes?”
“How would you use the cubes to show 2 times as many as Kiran's cubes?”
Student Response
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Advancing Student Thinking
If students show they may be thinking about the total amount represented on a card rather than making comparisons (for example, on Card K, they might see 4 groups of 3 in the two quantities combined), consider asking:
“What do you think this diagram represents?”
“Which situation does the diagram represent? How do you know?”
4.OA.A.2
Multiply or divide to solve word problems involving multiplicative comparison, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem, distinguishing multiplicative comparison from additive comparison.See Glossary, Table 2.
Multiply or divide to solve word problems involving multiplicative comparison, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem, distinguishing multiplicative comparison from additive comparison.See Glossary, Table 2.