In this culminating lesson, students apply what they learned in this unit to solve problems about surface area in context.

Students begin by looking at different examples of tents, analyzing two simple tents of different sizes, and reasoning about the amount of material needed to construct these tents. Then, they can create their own tent design and estimate how much material is needed for the tent. They need to ensure that their design meets specified parameters and their estimate is backed by sound reasoning and calculations. Finally, students present, compare, and reflect on their design solutions and estimates. They consider the impact of design decisions on the surface areas of their tents.

The activities in the lesson prompt students to model a situation with the mathematics they know, make assumptions, and plan a path to solve a problem (MP4) and to make a logical argument to support their reasoning (MP3).

Depending on instructional choices made, this lesson could take one or more class meetings. The Warm-up activity and the first activity about two camping tents can be completed in a typical class period. The last two activities (designing a tent and presenting the design) are optional and may take another class period or more, depending on the instructional decisions made, such as:

• Whether students use the provided information about tents and sleeping bags or perform additional research.
• Expectations regarding drafting, revising, and the final product.
• How students' work is ultimately shared with the class (not at all, informally, or with formal presentations).

A note about context: 

While experience with camping or tents is not necessary for comparing surface areas in the "Two Tents" activity, it might affect students’ readiness to design a tent in the subsequent activity. Consider showing additional images, videos, or an actual camping tent to orient students as needed. If the camping-tent context is anticipated to be challenging or sensitive (such as for students who have experienced housing insecurity or displacement), consider adapting the design task to be about a different structure or object. A tent for a party, a booth for a fair, a birdhouse or house for a pet, and packaging for a toy are some examples.