New way to multiply~!

Work Teaching English in Taiwan
1

Very interesting method…

http://www.glumbert.com/media/multiply

2

I can see how that works. XYAB makes XA, XB, YA and YB grids which you then count the intersections (eg 34 gives you 12 intersections) and add up. Just like long multiplication.

3

[quote=“x08”]Very interesting method…

http://www.glumbert.com/media/multiply[/quote]

It’s neat to see it that way. I remember doing almost the same thing in 1-3 grade with the stamp game.

Matt

4

[quote=“ILoveItHereButIDoMissSnow”][quote=“x08”]Very interesting method…

http://www.glumbert.com/media/multiply[/quote]

It’s neat to see it that way. I remember doing almost the same thing in 1-3 grade with the stamp game.

Matt[/quote]

I just re-read that and said, “Wow, Matt. You sounded like a schmuck there.” I didn’t mean it to sound that way. Just at 3:30 AM when you’re not feeling well, it does.

I was thinking I did something similar and it reminded me of that. But the paper method and the way it’s put down is really cool. So thank you for sharing :slight_smile:

Matt

5

Just learned this method…some freaky ass shit if you ask me.

mathforum.org/dr.math/faq/faq.peasant.html

6

wow! looks like a lot of extra work but cool still.

7

Both those just blew my mind, and both were easier to me than regular long multiplication. Cool.

8

Not quite. XYAB doesn’t make XA, but X0 * A0.

23 x 45

It’s not 2x4. It’s 20x40, 3x40, 20x5, and 5x3

I point that out because I think that’s one of the reasons kids have so much trouble with multiplication of larger numbers. They know they have to put the 0 in there, but often don’t see why.

Matt

9

I think as the numbers get larger it will become more and more impractical.

10

Yes, I know about the shifting. Adding the digits to the correct column was implied in the “adding them up in the right order” part. The partial products that I mentioned still have to be done.

11

Meanwhile, this is super-awesome: en.wikipedia.org/wiki/Trachtenberg_system

12

Haha. That Wikipedia author has my kind of sense of humor. :smiley:

13

Haha. That Wikipedia author has my kind of sense of humor. :smiley:[/quote]

Nope that’s really what happened. He did it all in his head without anything to write on. Later, he escaped from the camp and fled to Austria.

14
15

I’m impressed with the genius of it. I can’t immagine being in such a place and thinking of math, or of figuring it all out without wrighting it down. Amazing. But I hate math.

16

Ohhhhh…