In this lesson, students apply proportional reasoning to situations involving fractional values. First, students revisit scaled copies. They calculate possible dimensions for a scaled version of the United States flag. Then students review percentages. They determine the percentage of the flag’s area that is red, white, and blue for a variety of different flags from around the world.

As students compare multiple flags, they make use of repeated reasoning (MP8). As students explain their reasoning about the scaled figures or the percentages, they construct arguments and critique the reasoning of others (MP3).

The last activity is optional because it provides an opportunity for additional practice by combining the main ideas of the previous two activities.