Japanese Multiplication

[Dreamysyu]

Just an interesting trick I found on twitter. It isn't very practical, but looks fun.

So, do you know any other interesting tricks like that originating from Japan?

Edited January 26, 2018 by Dreamysyu

[tahu157]

I've seen this before. It probably works well if you grew up thinking and visualizing that way, but for the rest of us the amount of intersections gets out of hand pretty quickly as the amount of digits increases. I can't imagine anyone that didn't grow up with this method being able to do it in their head very well.

[Dreamysyu]

21 hours ago, tahu157 said:

I've seen this before. It probably works well if you grew up thinking and visualizing that way, but for the rest of us the amount of intersections gets out of hand pretty quickly as the amount of digits increases. I can't imagine anyone that didn't grow up with this method being able to do it in their head very well.

Well, of course it's not very practical if you aren't used to it. But at the same time, it's just fun to see that different peoples around Earth found different ways to do the same simple calculations. And, according to one of my calculus instructors at the university, who was obsessed with Japanese mathematics, it developed in quite a unique way during the time when Japan isolated from the West.

[WorldofAI]

From how I look at it, the gist of solving the problem isn't much different compared to how students here in the US are taught using the simple multiply-and-pad-0 method and the lattice box method. When the person divided up the different line intersections, it is similar to someone padding zeros. The division lines also resemble somewhat of the lattice box method.

The line intersection method as shown in the video would work best if students didn't get numbers that would require them to carry that 1 number over because that will make it confusing for students.

[Kurisu-Chan]

On 26/01/2018 at 9:28 PM, Dreamysyu said:

Just an interesting trick I found on twitter. It isn't very practical, but looks fun.

So, do you know any other interesting tricks like that originating from Japan?

You know, this reminds me of the Chinese multiplication technique, a pretty cool one, too. 

[VirginSmasher]

I've got some Japanese multiplication of my own.

Hentai + Slideshow games with plot = what I waste too much of my time on. 

[littleshogun]

Nice idea I guess, although I pretty much already used to the usual way to multiply though so unfortunately I can't understand the trick lol.