Mr. Avilla's student, Carla, explains with confidence in her voice, "You can't just compare how many blew bubbles in each class. It matters what it's out of. I can put 8/40 on the other number line by writing it as 4/20, because eight divided by two is four, and 40 divided by two is 20. Of course, 4/20 is less than 6/20." Pointing to the three labeled points on her number line, she concludes, "Class G did better than Class B, but Class A is even better because it has 6/20, which is more than 4/20."
This problem provides another chance for students to reflect on what they understand, practice using a number line to compare fractions that come from real-life data, and communicate about how to compare ratios. Carla's answer demonstrates to the other students that a peer student can communicate with confidence and in detail. Her words may help others articulate some of their own observations. Additionally, writing symbols to support her words will be beneficial both to her and to her listeners.