# Clip 2/11: Lesson - Part 1 Lipman School

## Overview

Teacher Joe Condon reads definition of rate developed and expanded by the class over the two-week period. Paralleling the initial lesson, students are again asked to name familiar rates. Condon then reminds students of one of the experiments from the Rate Palooza, using chopsticks to remove beans from a cup. The teacher gives them some data: in 20 seconds, Joe counts 30 beans, Sarah counts 25 beans, Alex counts 40 beans. Students are asked to write each piece of data as a rate, then justify who is the fastest.

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Teacher Commentary

Teacher Commentary

COACH LINDA FISHER: I am amazed to see how the class definition has evolved over time and the variety and detail of suggested rates. Whereas in the first lesson, few rates were suggested and many of them did not make sense, now everyone seems to have a variety of ideas and much to talk about. Students had a couple of strategies to justify that Alex was fastest. One girl talks about finding the unit rate, beans per second. I am also impressed that students build on each other's ideas by actively listening. "I used Kameen's idea about beans per minute, but I added numbers. Alex counts 2 beans per minute." Students who started with a very weak definition and understanding of rates can now use them articulately to justify ideas about fastest. Students seemed overall to use words to describe the units and the numbers in the rates.