The purpose of this activity is for students to practice finding the volumes of rectangular prisms, given a real-world context. The first problem provides a diagram like those students have seen in earlier lessons to illustrate the context. The other problems do not provide a picture, so students will need to visualize or draw a sketch of the situation. Going from the words of the problem to a mental image to a solution strategy are all important aspects of making sense of and solving a problem (MP1).

Because these are real-world problems, each rectangular prism sits on a natural base. Monitor for students who use this structure and the formula connecting volume to the area of the base and the height relative to that base.

• Ask selected students to share their solutions for the second problem.
• “How are the strategies the same? How are they different?” (Both get the same solution, but one person multiplied to get the base area and then multiplied the result by 5, and the other person chose to multiply first.)
• “How is the third problem different from the first two?” (It does not give us the length and the width of the closet. It just gives the area of the floor.)

The purpose of this activity is for students to solve a real-world problem that involves finding the volume of a figure composed of two right rectangular prisms. Unlike many other figures students have seen, this figure can be decomposed into two rectangular prisms in only one way. Students may rearrange the two prisms to make a single, long rectangular prism.

• Display the diagram of the garden from the Task Statement.
• Invite students to share how they found its volume.
• “If the garden is cut into two parts, what do the two parts of the garden have in common?” (Both are 2 feet tall and 3 feet wide.)
• “What is different about the two parts of the garden?” (The length. One part is 10 feet long and the other part is 8 feet long.)
• “How could you put the parts together to make a single rectangular prism?” (The sides that are 3 feet by 2 feet fit together and the length would be 18 feet.)