Returned the first homework – students’ mathematical autobiographies. This is the easiest assignment of the semester to grade, since I get to know the class and all that’s required are encouraging comments on each paper.
Started on units: which is a better upgrade –
- SUV getting 10 mpg to one getting 20 mpg
- sedan from 25 mpg to 50 mpg
All but one student guessed the sedan. That 50 mpg is so tempting.
It took a while for all to see that the size of the tank didn’t matter. The distance driven did. So we assumed explicitly that it was the same for each vehicle. That led naturally to why gallons per mile (or per hundred miles) was a more useful figure than miles per gallon.
Google calculator – showed how it did the unit conversions. (In Portuguese, which was the default configuration, I had the old – good – calculator interface).
Brief digression into scientific notation, then kilo and mega and why a kilobyte is 1024 not 1000 bytes.
Worked the Johnny’s deli homework exercise (2 million matzoh balls?) in class. Many students tried visiting Johnny’s (virtually, and on the phone) to get answers, or help. Turns out the web site claims only one million! That’s in fact believable at the high end of the estimates.
Finished by starting gas prices in Europe. Will continue that on Thursday. What else from the units chapter before moving on to (gasp) percentages?
Bottom line – the classes continue to be interesting – I think to the students, not just to me. We get less and less “done” and I have to remember that’s OK.
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