The purpose of this activity is for students to consider how the size of an object impacts the unit we use to measure the volume of that object. Since this is students’ first experience with these cubic units of measure, it may be helpful for them to see the actual length of a centimeter, an inch and a foot. Have rulers or cubes available to provide extra support to visualize the size of the cubic units of measure. Because there are no mathematically correct or incorrect answers, this activity provides a rich opportunity for students to discuss and defend different points of view (MP3).
The Launch of the activity is an opportunity for students to share their experiences and ask questions about the objects to ensure each student has access to the context. If it is helpful, display images of the items for students to reference.

• “How did you decide which units made sense?” (I tried to pick a unit that was not much smaller or much larger than the object being measured.)
• “What if I wrote only ‘24’ as the volume for the freezer? What questions would you have?” (I would wonder 24 what? If we don’t know the unit of measure, we don’t know how big the freezer actually is.)
• Display the measurements “24 cubic centimeters,” “24 cubic inches,” and “24 cubic yards.”
• “What is the same about these measurements?” (All are 24 units. All are cubic units.)
• “What is different about these measurements?” (They are different sizes. Cubic centimeters and cubic inches are a lot smaller than cubic yards.)

The purpose of this activity is to introduce students to the structure of the MLR4 Information Gap routine (also Info Gap routine). This routine facilitates meaningful interactions by positioning some students as holders of information that is needed by other students.

Tell students that first, a demonstration will be conducted, in which the whole class plays the role of the person holding the Problem Card. Explain to students that it is the job of the person holding the Problem Card (in this case, the whole class) to think about what information they need to answer the question.

For each question that is asked, students are expected to explain what they will do with the information, by responding to the question, “Why do you need to know _____ [that piece of information]?” If the person holding the Problem Card asks for information that is not on the Data Card (including the answer), then the person holding the Data Card must respond with, “I don’t have that information.” In explaining their answers, students need to be precise in their word choice and use of language (MP6).

Once students have enough information, they solve the problem independently.

The Info Gap routine requires students to make sense of problems by determining what information is necessary and then asking for the information they need to solve them. This may take several rounds of discussion if their first requests do not yield the information they need (MP1).

• Invite 1–2 students to share how they solved the problem.
• “What were the important quantities to know to solve this problem?”
• “Which questions that you asked helped you find those quantities?”
• “Were there any questions that the Data Card cannot answer?”

The Info Gap routine in this activity gives students an opportunity to determine and request the information needed to measure the volume of a rectangular prism, using units of different sizes. 

The Info Gap routine requires students to make sense of problems by determining, and then asking for, the information necessary to solve them. This may take several rounds of discussion if their first requests do not yield the information they need (MP1). It also allows students to refine the language they use to ask increasingly more precise questions until they get the needed information (MP6). 

• Share the correct answers, including the units, and ask students to discuss the process of solving the problems.
• “What questions did you ask to help you find the volume?” (What is the height of the dumpster? How much space does Jada have in her backpack?)
• “What were the important quantities to know to solve each problem?”
• “What units were used for each problem? Did those units make sense?” (Cubic feet and cubic centimeters. Yes, because a dumpster is big and a juice box is pretty small.)
• “Were there any questions you weren't sure how to answer?” 
• “Did anyone solve the problem in a different way than their partner?”