It examines a German teacher's YouTube video about a multiplication method that was taught in Germany more than a century ago -- some middle-aged and senior commenters remember their grandparents having shown it to them once. It's also called Russian Peasant Multiplication.
With it, you can multiply any two integers without knowing how to multiply. All you need to know is how to multiply and divide by 2, how to add, and how to tell whether a number is even or odd.
Just thought the more math-minded here might find it interesting.
SPOILER: it's based the binary multiplication algorithm.
The impression I get from Lehrer Schmidt's video (it's in German with no subtitles) was that it was how multiplication was taught long ago but I didn't catch how long ago that was supposed to be -- judging by the age of commenters who mention a grandparent having shown it to them (ie, middle-aged and senior), I would guess that was in the late 1800's.
I would assume that regular long multiplication would have been taught too, or maybe for the students destined for higher academics while the farm children were given this (big assumptions). Also in my 1914 copy of The Walsh-Suzzallo Arithmetics primer (for grades 1 to 6 or 8, going from counting up to keeping a store's accounts), I see at all levels many mental calculation drills to be done in class. With that in mind, I could see methods like this being taught as supplemental methods to make all that work by hand quicker and easier and less prone to error, as well as accessible to those whose multiplication table skills are weaker.
I just thought how neat it was that it's based directly on the same binary multiplication algorithm that I had learned in my computer training.
Here's that YouTube video. Remember, it's in German with no subtitles. And, yes, that is how they write ones, sevens, and nines.
I just noticed the past tense. Sorry. There have been so many things after his death that I would have wanted to share with my father.
Does that "frozen wasteland" where you're from happen to be in Manitoba, maybe around "The Peg" (Winnipeg)? When I was stationed due south from there in northeastern North Dakota I learned about the "Germans from Russia" who settled heavily in that area. The story I was told was that the Russian government recruited German farmers to colonize and develop the Ukraine with the promise that they'd be left alone and not treated like Russian serfs (who weren't freed until 1861). But then about a century later politics changed and Russia started treating them like Russians, many emigrated to the US and Canada and settled in the prairie that was so much like where they had come from.
There is a very well presented site here in South Africa that we visited the other day. We did not go to any of the caves, we just went through the visitors center. The information was well presented and presented in a way for adults to children to enjoy and learn. https://en.m.wikipedia.org/wiki/Cradle_of_Humankind
Does that "frozen wasteland" where you're from happen to be in Manitoba, maybe around "The Peg" (Winnipeg)?
No, right next door in Saskatchewan.
The story I was told was that the Russian government recruited German farmers to colonize and develop the Ukraine with the promise that they'd be left alone and not treated like Russian serfs (who weren't freed until 1861).
That's how my father told it too. On top of that , my ancestors were Mennonites (pacifists) and the Russians already had more military manpower than they needed. They got out before WWI so they missed most of the troubles.