This culminating lesson is optional. Students use what they have learned in this unit to create a scale floor plan of their classroom.

First, students plan and measure. In groups, they decide on necessary measurements to take, plan the steps and the tools for measuring, and carry out their plan (MP1). Next, students make calculations and draw. They choose their scale and method strategically, given their measurements and the constraints of their paper. Then, students reflect and discuss. In small groups, students explain their work, compare their floor plans, and evaluate the decisions they made in creating the scale drawing (MP4). As a class, they reflect on how the choice of scale, units, and paper affected the drawing process and the floor plans created.

Depending on the instructional choices made, this lesson could take one or more class meetings. The amount of time needed for each part might vary depending on factors such as:

• The size and complexity of the classroom, and whether measuring requires additional preparation or steps (such as moving furniture, taking turns, etc.).
• What the class or individual students decide to include in the floor plans.
• How much organizational support is given to students.
• How the students' work is ultimately shared with the class (not at all, informally, or with formal presentations).

Consider further defining the scope of work for students and setting a time limit for each part of the activity to focus students’ work and optimize class time.