Math teachers at a community college are not paid to create new mathematics. We are not supposed to invent math but teach what exists. This does not mean we can’t be creative, we can. But the creativity should be confined to how we teach, not what we teach.

I give my creativity freely to anyone who teaches. I not only give worksheets to whoever asks, I’ve put up a few of them on this website. I will describe my examples freely–so freely I suspect that I bore people. Some of my favorite examples may be pretty common:

When teaching exponential growth I use credit card interest and figure out how much a student will owe on his credit card if he doesn’t pay it off.

I introduce logarithms by asking how to determine the number of rounds left in a single elimination tournament if the number of teams is known.

When teaching the mathematics of apportionment, I discuss how many teachers will be assigned to each school, based on the student population.

One example of Newton’s law of cooling, has a cast of characters including Victor “Vic” Timm, who dies, his fiancee Mary Ritch, His sister Molly Gunn (although no one seems to know what a gun moll is any more) and her son, Carey A. Gunn. The body is found by Tom Peepers. Unfortunately, these jokes are totally lost on the non native English speakers in my class. This is the only case I use terrible jokes in a problem.

I enjoy finding interesting examples. I hope I never have to teach a problem starting “Seven years ago, John was twice as old as Mary.” Who cares?

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This entry was posted on April 27, 2010 at 10:28 pm and is filed under Age, Teaching. You can follow any responses to this entry through the RSS 2.0 feed.
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May 14, 2010 at 10:32 pm |

Hi. Can you expand what you said about how you teach logs? “the number of rounds left in a single elimination tournament if the number of teams is known”? This sounds like a great way to teach logs. I found this year, which was my first year teaching 11th grde algebra2, my kids liked solving logs, but I know I could have done a better job by giving more word problems involving logs. All I gave were the standard earthquake and pH scale problems (ZZZzz).

May 14, 2010 at 11:15 pm |

If you don’t know what the single elimination tournament tree looks like, google “single elimination tournament” under images to see the tree. I start with 16 or 32 original teams. I work from left to right and put the number of teams in blue above the column of teams. (You can put the name of your school on one blank and follow it through to be the winner.)

Below the column with one team, I write 0 in red, because there are 0 rounds left. When there are two teams, I write 1, for one round left. For four teams I write 2, etc. I ask them for the remaining numbers.

I then try to get them to find a function from the red numbers {0,1,2,3,4} to the blue numbers {1,2,4,8,16}. Sometimes they find 2^x, but often I have to tell them. Then I tell them I want the inverse function. We studied inverse functions in the previous section. I define log to the base 2 as the inverse of this function. Log to the base n would work if you had n competitors, such as in a race.

I hope this helps.