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[Mathematics] Uncle Josh gets punchy

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I despise clickbait. I shun it from my Facebook feed, and I am hoping one day to find a Chrome extension that wipes all those “links you may like” boxes that take up valuable web page space.

Unfortunately, the damn stuff works.

So why not use the technique for some good:

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Of course, without the picture of a babe in a bikini that has nothing to do with the article, the tactic may fail.


Last minute update. I couldn’t leave well enough alone:

She needed to find the slope of a line...

Uncle Josh was pleased with a mathematical statement last night

By now you have seen this meme, which has a note from an “exhasperated parent” over the complicated way kids are being taught math. We are supposed to applaud this jerkwad behavior because for some reason stupidity is seen has honorable.

There is another one floating around that is a damned good problem, and the thing we’re supposed to applaud is a parents complaint that they don’t get it and there is an “easier way” which is the good old fashioned new math carryover method Uncle Josh learned.

Then, last night, in choir rehearsal, we read through a piece by Orlando Gibbons. Gibbons’ was listed, as is often done in musical scores, with his life span (1583-1625). The bass I was sitting next to said–in this order–“25 plus 10 is 35 plus 7…he was only 42, a very young man.”

Uncle Josh was very, very happy to hear this (not that a young man died at age 42, but the calculation method). This is the mental math many of us learn, once we understand the carryover method and practice with it enough, we get a sense of the numbers and realize, as the first article I linked to points out, subtraction finds the distance between numbers.

I don’t remember ever being taught this add-the-easy-distances method, but I discovered it, and i practiced it, and I use it today in my day job.

So, we’re supposed to be angry that we’re teaching kids to subtract? I think not.

Japanese “Magic Math”

Lifehacker posted an old video of an old technique, and it made Uncle Josh cry a little. The tears were not that this old video was being trotted out again like it was something new, or that on first read Ms. Pinola made it sound like this is how Japanese students actually multiply numbers. No, the tears come in the third paragraph:

I don’t know how or why this works. But it’s a pretty amazing trick and might make you wonder why we don’t teach math the way Japanese teachers do.

This isn’t magic, and it’s not anything special. It’s a technique used to illustrate how the various steps of multiplication work for visual learners. It is estimated by Aunt Stephanie that there are more visual learners than auditory or logical learners. (To be fair to Aunt Stephanie, she does not claim to have hard data to back this up, but she was also home in bed nursing herself to life when I asked.) I suspect that the Japanese, having a pictographic writing structure, probably have a few more visual learners by population than Americans. I do know that the Japanese overall structure takes more time with individual concepts, so students have true mastery over their subjects instead of the “master this by next week” mentality my education hit me with.

Standard math, as I learned it, works perfectly fine and simply does this trick without a bunch of lines and counting.  It does, however, include some of the sub-steps of multiplication of single digit multiplicands, which every student should be able to do by memory.

The comments to her post say much of the same thing: This isn’t new. This isn’t uniquely Japanese. This ain’t magic.

But it is sad that Ms. Pinola has to make it mysterious. To be fair to her, other writers have said this same thing: Jesus Diaz on Gizmodo (linking to the same video it appears) also writes:

Then I tried it and it works perfectly, but still can’t understand how it works—or how anyone found this method.

Oh, how I weep.

But my job is not to weep, but to explain, which I shall not do, because the inimitable Vi Hart has already done so:

Perhaps if we didn’t rush our math students to test taking strategies and taught them mathematics, we wouldn’t have this kind of stuff floating around.

  • See http://www.learning-styles-online.com/overview/ for more information about learning styles.