The purpose of this activity is for students to find different ways to arrange 60 shipping containers. They decide which arrangement is the best in the context of shipping 3,300 tons of garbage.

• Invite previously selected students to share their display.
• “What arrangement does this group’s display represent? Why might they think this is the best arrangement?” (3 rows of 10, stacked 2 containers high. They might think it's the best arrangement because it's long and narrow and not too tall, so it would probably fit well on a cargo ship.)
• “What can you tell this group that may make them change their decision?” (It’s too tall and might start falling in the water. It’s too wide and might not fit. It’s too wide and might not leave room for anything else.)
• Consider asking, “How much trash do you think is in each container?”

The purpose of this activity is for students to estimate the number of shipping containers on a cargo ship. First, students estimate the number of shipping containers on a partially loaded cargo ship. Then they discuss assumptions that could affect their estimates before they estimate the number of shipping containers on a fully loaded cargo ship. When students consider assumptions about information not given in a situation, they model with mathematics (MP4).

• Invite students to share their estimates and any assumptions they made.
• “How could you improve your estimate?” (Recreate the ship, using a model. Check the height, the width, and the length of the container arrangement. See how many are on one side of the ship and multiply that to get a closer estimate.)