*Playing with Math: Stories from Math Circles, Homeschoolers, and Passionate Teachers*) is done. I haven't even been reading the blogs on my feedly list regularly. I had to stop to get focused on the book this summer, and then I guess I just wanted a break. I caught up yesterday and today. (My Veteran's Day gift to myself.) Now I need to make a list of everything lovely that I found...

- I often enjoy Gary Antonick's NumberPlay column (each Monday). I especially like logic puzzles, so solving this one should be fun.
- Polar curves in nature... I wonder if the math might help explain the shape?
- This "which would you pick" question is a great intro for expected value for statistics.
- GSWP describes lots of different kinds of critical thinking.
- Fawn Nguyen is brilliant. This is a place-value puzzle that got her whole class thinking hard.
- I love the Mighty Girl profiles I see on facebook. I wonder if this book they recommend is good: Infinity and Me
- A good article on Steven Strogatz in the classroom, which mentions some very interesting free curriculum.
- Hmm, I wonder if my son would try this maze puzzle, called Ogleboro City ... I'll print it out and see.
- I've played with this problem a little. I want to play with it more. Dan Finkel took the basic problem and posed a bunch of variations. Facinating! It might lead to another math circle topic...
- These gifs are making the rounds on Facebook.
- Henry Segerman makes fascinating mathematical artwork using 3D printing. While honing the description of the piece we'll be featuring in
*Playing with Math*, I can across his 100 prisoners and a lightbulb paper. The puzzle posed seems impossible, but... - Here's a much easier puzzle from 9gag (found on Facebook).

And I'll end with a request. Would someone please teach me to use a slide rule? I know it's a totally archaic skill, but I think it would help me explain logs to my students.

I had a long post on how to use a slide rule, but it seems to have been both too long and edible to the internet gremlins.

ReplyDeleteCheck out http://sliderulemuseum.com/SR_Course.htm which not only gives a self-directed course in using a slide-rule, it has information on a classroom slide-rule loaner program.

I don't want a course. I want a tutor. I'm sure I'll catch on quickly.

ReplyDeleteIt's so weird. It seems like it must be pretty straightforward, and I try to figure it out, and am just stuck. (Now I'll be embarrassed when I learn, I bet.)

I'm not sure what you want in a tutor, and how a tutor (especially over the internet) would be different than a book.

DeleteI mean, I can tell you that the method of multiplying two numbers is to use the C and D scales (which each represent the log of the marked numbers), but so can the course/book I linked to. I can't put one in your hand and show you, since we aren't close (I'm a New Yorker, you're a Californian).

Let me know how I can help.

Thank you! We could skype, and use the online slide rule I pointed to.

ReplyDeleteMy email is mathanthologyeditor on gmail.

ReplyDeleteWhen you figure out the slide rule, it might be interesting to see what you think was blocking you. One guess is that it is simply the number of rules on most commercial versions that can obscure the basic functions. Just knowing how the rules are labelled might be enough (which is on wikipedia here: http://en.wikipedia.org/wiki/Slide_rule)

ReplyDeleteLogarithms are great for calculating, but in the modern world I think the pedagogical value of this fact is very limited. In other words, students won't care that they can do calculations by using a slide rule when they have much more powerful tools. As an alternative, you might talk about log scale graphs for processes that compound (for example, many biology models and financial values). For a specific example, the stock market rising 10% one year should be presented to look the same as a 10% rise in another year.

Why else might we care about logs? They let us look across orders of magnitude on a single picture, like Terry Tao's presentation on the cosmic distance ladder.

Do any of these things resonate with your students?

I agree that calculating is of minor interest. I like explaining the history as context, and I'm thinking knowing how a slide rule works would help in that regard. I like your examples, and my students might. I have often shown them the powers of ten video in the past, though I didn't this semester. Is Terry Tao's like that?

DeleteTerry Tao's cosmic distance ladder is something of a subset of the powers of ten. Most of his presentation talks about how we can measure or consider distances on cosmic scales. He has several slides where he has distances of different orders of magnitude presented together and, of course, the way to do that is to think logarithmically.

DeleteIn the spirit of concrete-pictorial-abstract, maybe the slide rule is the manipulative high school students are missing?

BTW, I don't want to dismiss calculating (or elements of calculating) entirely as a motivation. I know at least two nerdy kids (my middle child and me) who got a kick out of different calculations we could suddenly do easily with a log table.

Thank you, Buddha! That was great! I will definitely keep playing with it.

ReplyDeleteI just came across this post. Did you come to terms with the slide rule yet? They are really very simple and incredibly smart inventions, and yes, they will help you to explain logarithms. That is their operating principle.

ReplyDeleteI'm a retired engineer (Class of '68). We began to get electronic calculators while I was in graduate school. From the 10th grade in high school onward I relied on slide rules to get me through.

I still have my beloved Post Versalog slide rule. It's made of bamboo, of all things. You know how people are raving nowadays over the qualities of bamboo as a design element? Heck, we engineers have known that forever. There never was a better slide rule.

I'm posting anonymously, but I'm Charles Hethcoat. You can email me at chethcoat@oplink.net if you'd care to continue the discussion. We can walk through the design and operation of the slide rule.

CH

I had a Skype lesson with Buddha Buck - he was great, and I understood a lot. Unfortunately, I didn't practice right after, so I may have lost it. I think I should buy myself a slide rule, and play with it this summer. But if I need help, I now have a second willing tutor. Thanks!

ReplyDelete