Wednesday, January 9, 2013

Day 77: Examples & Practice

Trying VERY hard to stress the meaning of sine, cosine, and tangent this year. To that end, I'm insisting on using language like "the sine ratio for a 25 degree angle is equal to 0.4226" as we read "sin 25 =0.4226."

I still haven't mentioned that these ratios can be found using a scientific calculator (and I don't have any immediate plans to do that), so I'm requiring students use the trig tables I've provided. Some students know how to use the calculator, and that's fine, but my theory is that a greater understanding is achieved through the table.

Also stressing the use of a mnemonic to help remember sine = opposite / hypotenuse and the like. I know everyone and their brother uses "SOH CAH TOA," but I've found that while most students can repeat that phrase, MANY of them will misspell it, which immediately defeats the purpose. Last year, a student suggested "Some Old Hare Came A Hoppin Through Our Apartment" which I immediately fell in love with. Much less room for error, except most of my students don't know what a "hare" is, so I changed it to "hipster." I also made a large poster of the phrase and hung it visibly where all can see.

What's funny is that the poster has been up all year. Some kids have asked about it, and I simply said we'll explain it when the time comes. But a lot of kids expressed a fair amount of surprise that it even existed. These are the same students that haven't noticed the 4' x 8' whiteboard devoted to a weekly calendar for the class, can't seem to remember where to find extra copies of worksheets, and don't understand how to use the Turn-In Bin properly. *sigh*.

Anyway, today the students worked on Unit 5 Worksheet #2 practicing sine/cosine/tangent problems after seeing some examples worked through.