standard_description: Subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90 (positive or zero differences), using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.
problem_activity: Narrative
The purpose of this warm-up is for students to notice that figures composed of two right rectangular prisms can be decomposed in different ways which will be useful when students find the volume of figures composed of two right rectangular prisms in a later activity. While students may notice and wonder many things about these images, comparing the side lengths of the two figures is the important discussion point.
Launch
Groups of 2
Display the image.
“What do you notice? What do you wonder?”
Activity
1 minute: quiet think time
1 minute: partner discussion
Share and record responses.
Student Facing
What do you notice? What do you wonder?
[IMG]
[IMG]
Student Response
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Activity Synthesis
“Do you think the pictures show the same figure? Why or why not?” (Yes, they look the same. Yes, I can use the given side lengths to calculate that they are the same.)


aligns: no