## Wednesday, May 18, 2016

### Logarithms, or, It Was A Good Day

A month or so ago, many of my pre-calculus students didn't do so well on a test on logarithms.  At all.  Do you watch Game of Thrones?  Did you see the Red Wedding episode?  Yeah, it was kinda like that.

They're too wedded to their calculators--which didn't help much on the "no calculator allowed" portion of the test.  A couple of weeks ago I put them through my 5-day "logarithm boot camp".  I taught them how to use a logarithm table, and then we get going.  By the 5th day they were smoothly solving problems that, before, they might have been able to solve with a calculator.  I wouldn't say they were solving such problems with ease, as the problems most certainly were not easy, but they were solving them confidently and correctly--and that's plenty good.

Final exams are coming up next week and we're deep into review.  I don't have any logarithm problems on the final exam but don't want to leave the topic out of our course review, so today we played Logarithm Jeopardy.  I had downloaded a PowerPoint of a Jeopardy template, made up categories and questions, and the game was on.

I wish you could have seen them.  I had kids all over the class, working individually or in groups, answering the questions and solving the problems.  Sometimes they'd make mistakes, and that's OK--because as soon as I'd start to explain the answer they'd see their mistake, cut me off, and tell me what their mistake was.  Most of them were getting the answers correct, though.

Confident and correct.  And excited to be answering those questions.  My students were excited to be answering questions about logarithms.

It was a good day.

Anonymous said...

How could you teach a no-calc class on logs without bringing in some slide rules?

I'm disappointed. :)

BB-Idaho said...

Well THAT made me dig out 'Standard Mathematical Tables' (1957 edition) from my library! It seemed pretty well worn, so we must
have done considerable work with logs in HS. Back then, you didn't mess with natural logs until college, and then mostly in physics and chemistry, but they DID let us use our calculators: they were called log-log slide rules and I still have some gathering dust.

Darren said...

I have slide rules, and I show how the C and D scales on them are created using logs, which leads to multiplying by adding the logs. I don't teach slide rules more than that, though.