standard_description: Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. Use benchmark fractions and number sense of fractions to estimate mentally and assess the reasonableness of answers. For example, recognize an incorrect result 2/5 + 1/2 = 3/7, by observing that 3/7 < 1/2.
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