standard_description: Apply properties of operations as strategies to multiply and divide. (Students need not use formal terms for these properties.) ^( )Examples: If 6 × 4 = 24 is known, then 4 × 6 = 24 is also known. (Commutative property of multiplication.) 3 × 5 × 2 can be found by 3 × 5 = 15, then 15 × 2 = 30, or by 5 × 2 = 10, then 3 × 10 = 30. (Associative property of multiplication.) Knowing that 8 × 5 = 40 and 8 × 2 = 16, one can find 8 × 7 as 8 × (5 + 2) = (8 × 5) + (8 × 2) = 40 + 16 = 56. (Distributive property.)
problem_activity: Narrative
The purpose of this How Many Do You See is to allow students to use subitizing or grouping strategies to describe the images they see. In the synthesis, discuss what students know about the How Many Do You See routine and what they need to think about to create one like this example.
Launch
Groups of 2
“How many do you see? 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.
Student Facing
How many do you see? How do you see them?
[IMG]
Student Response
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Activity Synthesis
“What do you know about How Many Do You See?” (They have dots arranged in groups that make the dots easier to count. There are many different ways to count the dots.)
Consider asking: “What would you have to think about if you were going to design a How Many Do You See like this one?” (How the dots are organized. How to create groups of dots that are easy to count. Different ways that the dots could be seen.)
Record and display responses for all to see.


aligns: no