Friday, March 21, 2014

The Latest Stupid Way To Do Simple Math

Let me begin with a short addition to yesterday's post.  It's ok to teach the "shortcuts" in math--change the inequality sign when multiplying/dividing by a negative number, "invert and multiply", "a negative times a negative is a positive".  What's absolutely not OK is to teach those shortcuts but not to teach why they work. 

There are some algorithms, though, that are so handy, so useful, and so easy to learn, that they can reasonably be taught as "this is the way to do it".  Third graders don't need to understand why the long division algorithm works, they just need to learn it (and it is possible, but perhaps it requires a superteacher like Mrs. Barton for all students in a class to learn it).  They should learn multi-place multiplication, too.  They should learn the algorithms that have been used for centuries not because they've been used for centuries, but because they work and are the most efficient algorithms humans have come up with.  When someone comes up with a better algorithm for division, I'll support it, but until then I'll merely applaud those who search for one. 

This algorithm is not "the one".  Holy crap.  Is there any rational, sober person who honestly thinks this method is better, easier to learn, and/or more efficient than the so-called traditional method?  The academics who came up with that have been out of 3rd grade too long.  Mrs. Barton would look down her nose at that method--and continue to teach students as she always had, which was effectively.

6 comments:

Ellen K said...

Oh I can top that. My friends in the Foreign (OOPS) World languages classes were told that the new paradigm for teaching Spanish, French, German and Latin is a "total immersion" classroom. First of all, whoever is mandating this stuff doesn't realize that NOBODY SPEAKS LATIN. Ok. Then there's the oddity that our ESL/ELL students are supported by bilingual programs from PreK to graduation because the official position is that total immersion doesn't work. So what makes them think that kids who speak English will learn Spanish faster using such methods? How come ESL/ELL students are not treated the same way?

30,000 ft said...

Off subject. Opinion about cursive no longer being taught.

maxutils said...

Ypu know ... I wanted to be super upset by this, and I'm very disappointed that I'm not. essentially, the only way this is different is that is that it gives you a strategic way to make what otherwise might be a difficult first guess ... I wouldn't suggest teaching it that way, but perhaps as a backup plan if you didn't think you could make a good guess ... I never knew why the long division algorithm even worked until I started teaching synthetic. In general, though ... why should come first, shortcut comes second ... times tables up to 12, memorized.

Jerry Doctor said...

My head is still hurting from reading the "study." First of all, the numbers don't add up. They had 8 students take all four quizzes. Since there are two questions per quiz, these students answered 64 questions. The 5 students that took 3 quizzes answered 30 questions. Six students took 2 quizzes - 24 questions. Five took one quiz so another 10 questions. That accounts for all 24 students and gives a total of 128 questions that were answered. But the results show a total of 130 questions.

Next, you gave a maximum of eight "whole number division" problems to college students and they only got 60% right??? Oh... never mind. I forgot. They are education majors.

Most important: Are they serious? Really? If you want the students to be able to multiply and divide using addition and subtraction, teach them to use logs. They'll understand that as well as they will this!

Jerry Doctor said...

30,000 ft: You have no use for cursive when your signature is an X.

Ellen K said...

Not just cursive, but handwriting altogether is only given cursory attention. (no pun intended)I can barely read the handwriting of some of my high school students. The irony is that for dyslexic kids as well as ADHD kids, slowing down to concentrate on making the shape of the letter helps. Scottish Rite Hospital helps thousands of dyslexic kids using this approach.