kitchen table math, the sequel: Andrew Gelman wants to know what to cut from h.s. math

## Saturday, November 5, 2011

### Andrew Gelman wants to know what to cut from h.s. math

He doesn't seem to know about any of the changes to K-8 math in the past 20 years, and the blogger he quotes, Mark Palko, explicitly rejects the math wars as a "clever narrative" that does not explain high school math curricula.

It's tough fighting a math war nobody knows about.

In any event, some of you should probably weigh in on which topics to include in a sound high school math curriculum.

bky said...

The deadwood I see in my kids 8th grade algebra class is all the stuff that is not algebra. They have spent a lot of time doing basic statistics (mean, median, mode, box-and-whisker plots, etc) but always on made up data with no attempt to see what the statistical concepts, eg outliers, means to the domain of application.

I would replace synthetic division by the method which anyone who really ever divides polynomials probably uses, which is to write down the factor you are trying to divide out and start multiplying by terms that you know you need, then subtracting off what shouldn't be there, etc. It is the same as synthetic division except that it is more rough and ready. It builds up strategic thinking and so on, plus it gets the job done.

Don't ask engineers if they ever do synthetic division or otherwise divide polynomials. Who cares. Algebra students need to be able to divide polynomials. If you know one root of a quadratic, how to you find the other? How do you prove there is another? How do the coefficients relate to the roots? Polynomial division is a key tool. Kids should learn to manipulate expressions. Polynomial division is a good instance.

lgm said...

Yes, cut the review of 6-8th grade material such as percents and ratios and the geometry topics. Move unprepared students into their own double period section and put the review there - only call it reteach, which is what it really is. Let those who have the ability and background move on. Rationalizing the denominator (listed in the link) isn't even in Alg I here..the course never gets that far.

Anonymous said...

Synthetic division is really useful for determining whether or not you've found the largest root.