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Standard 2: Reason Abstractly & Quantitatively

Clip 10/13: Standard 2: Reason Abstractly & Quantitatively Using Rates Part 1P


Mathematically proficient students make sense of quantities and their relationships in problem situations... Quantitative reasoning entails habits of creating a coherent representation of the problem at hand; considering the units involved; attending to the meaning of quantities, not just how to compute them; and knowing and flexibly using different properties of operations and objects.

Joe Condon presents a lesson study for 6th grade students and observing teachers to identify strategies for comparing unit rates. In these clips, he starts by establishing classroom norms for active listening. Then he engages the class in a whole-group experiment of the teacher power walking a 5-meter strip. The members of the class are given jobs for collecting data or monitoring time. Then Condon uses a ratio table to talk about rate and find equivalent rates and unit rates. Students are asked to name some familiar or common rates. Students then try to give their own definition of rate after looking at these examples. Finally students are given a ratio with no words and asked what it could mean.

Students conduct 3 rate experiments: stringing beads on a shoelace, picking up cubes with chopsticks, and counting rice. After the experiments the teacher debriefs the results as a whole class. "Who won?" "Why can't we tell from the raw data?"

See this video in the context of an entire lesson.

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