Class 2 Thursday, Sep 4 2014

Trying to flip the classroom, again. It’s hard, with 24 students and no tutor.

The class worked in groups of 3 (the tables) on one of the homework problems: Exercise 1.8.15:

In her September 26, 2011 review of Michael Lewis’ book Boomerang Michiko Kakutani wrote:
Greece, Mr. Lewis writes, ran up astonishing debts – . . . – that came to “about $1.2 trillion,
or more than a quarter-million dollars for every working Greek.”

  1. Use Lewis’ statement to estimate the population of working Greeks at the time he wrote the article.
  2. Use the web to find the national debt and population of Greece (for 2011 if you can, now if you can’t).
  3. Do the answers to the previous two parts of this Exercise agree? If not, what might explain any differences?
  4. Compare Greek per capita national debt to that in the United States.
  5. Here’s a political question: is large national debt a bad thing? You can find both “yes” and “no” answers on the web. Here’s one place to start:>.What did you learn from this article?

Several groups realized that to answer (a) you had to divide something by something else, but didn’t know how to decide. So I explained separately to several groups that you could start with the units. You knew total debt ($) and the rate ($/greek) and wanted the number of greeks:

1.2 trillion $

—————–  = 250,000 $ per greek

? greeks

That tells you what to do next – cross multiply, then divide by the 250,000 $/greek. That’s not the Chapter 2 strategy in the book, which would rely on understanding how to cancel units. I think that in this case it’s even better. I should probably put that into the book, or at least into the instructor’s manual. I wonder if I will get around to that.

Getting even that far, several students (groups) had trouble figuring out what the question meant. That provided an opportunity to stress the fact that this is a course in reading and writing, not in what they think of as “mathematics” – and that for many of them that should be a plus, since they can read and write even if they don’t think they can do math.

I finished by expanding that into a discussion of what I hope/expect in their written homework.

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