Saturday, October 27, 2012

Friday Favorite: Sound Buttons!

There are moments in the classroom that call for spontaneous applause, or canned laughter, or a drum roll.

For years I have had this urge to play sound effects in class. I never figured out how to pull it off, until recently.

I was playing with my new phone the other day when it occurred to me that there is probably an app for that. Sure enough, there is! If you search for "sound buttons" or "sound effects", you will find that there are tons of options to choose from. I have tried a few. I don't know if the one I am trying out is going to be my favorite, so I am not recommending a specific app at this point. They all look something like this:

Anyhooo . . . . imagine this:

*Gong* Bell work is over.

*Bugle call* Time to learn new math!

And there's a fraction . . . *Evil laugh* or *man screaming*

That's the right answer, Johnny! *Applause/WooHoo/Bingo!/Yes!*

I'm sorry, that's incorrect . . .*Buzz*

I am having wayyyy to much fun with this thing!

In related news, my students were smiling as they worked away on completing the square . . . with fractions . . . on a Friday . . . after losing a big football game the night before.

Factoring ax^2, Teensy Tweak

Sometimes, it is the littlest change that makes a big difference. I feel like I am splitting hairs here, but this adjustment to the airplane method helped my students tremendously this year. I've written about it before, but here it is with an ity-bity change that seemed to help:

Say you are trying to factor this . . .

You start by putting 2x in the front of each binomial. This feels wrong. It should.

So, to cancel out the extra 2, you divide by 2 right at the beginning. This was my teensy tweak. I used to have students do this at the end. It makes more sense here, and students are less likely to forget.

Then continue normally, multiply a and c. Find two numbers that multiply to get ac and add to get b. Put these at the back of each binomial.

Then, with the two already hanging out there, you just look for which binomial can be reduced by 2.

Ta daaa.

In this situation, the 6 has to be split into 3 and 2 before reducing.
Students didn't have any trouble with that.

Disclaimer:  This is not my method. I saw it first while observing another teacher. I have seen others write about it as well, so I am not sure where to give credit. 

Saturday, October 6, 2012

Factoring Before You Know How

Factoring has been my nemesis for years. I don't think I have taught it entirely the same way twice. My students arrive in Algebra 2 with some experience in factoring, but I always feel like many of them are learning it from scratch.

This year's changes to the factoring extravaganza include adding in this activity, where students try to match two binomials to each quadratic:

I had students do this matching activity before I gave them any specific factoring strategies or rules (we had previously reviewed multiplying binomials). I wanted them thinking about the question "What two binomials multiply to get this polynomial?"  I wanted them to develop some intuition about factoring before I hit 'em with a specific method.

After ten minutes of this, a few groups were finished. The rest were making progress but it was a struggle. "Isn't there another way to do this, Mrs. Gruen?" Well, yes there is, I am so glad you asked! And then I showed them the airplane method, which I tweaked a tiny bit this year (I will write about that soon). And they just ate it up.

Here are the files:
Binomial Tiles Factoring Work Mat #1 Factoring Work Mat #2