kitchen table math, the sequel: Too Cool

Monday, July 16, 2007

Too Cool

From Tony via Darren at Right on the Left Coast



Easy Graphical Multiplication Trick - video powered by Metacafe


No, I still don't Everyday Math.

11 comments:

Independent George said...

I can't help but notice that the largest digit being multiplied in either example is '3'...

concernedCTparent said...

This is vedic math. Quite fascinating. I explained the "all from nine and the last from ten" principle to my kids and they thought it was brilliant. It's quite interesting and coming to a mathmonkey center near you. www.mathmonkey.com/ Move over Kumon!

Doug Sundseth said...

I can't wait to the see the video showing the use of this technique to 94.88 * (27 + 4/7).

And let's not even think about how to explain division as a reverse of this procedure.

Barry Garelick said...

Anyone know how to program the routine into a computer? I'd do it, but the last language I learned was FORTRAN and I understand things have improved.

SusanJ said...

Barry, what do you want to program? The graphics?

This is just a visual way of doing the problem by FOIL

21 * 13 =
(20+1) * (10+3) =
2*1*10*10 +
(2*3+1*1)*10 +
1*3

SteveH said...

I'm with Doug.

It looks like a lattice method for those who can't multiply 2 times three. They can only count lines.


"... the last language I learned was FORTRAN and I understand things have improved."

Not much, but as an old punched-card carrying FORTRAN programmer at Michigan, at least the cards went away.

Barry Garelick said...

Not much, but as an old punched-card carrying FORTRAN programmer at Michigan, at least the cards went away.

How well I remember those days. Did you have Dr. Galler for any of your computer classes?

SteveH said...

"Did you have Dr. Galler for any of your computer classes?"

That name sounds familiar, but I can't say for sure. I just remember that the first course in programming washed out a lot of students. But the real killer courses were Operating Systems and Compiler Design; students had to program them. This was back when the computing center was on the central campus. I still remember sitting there staring at the monitor in the corner and watching my low priority job get pushed back.

The real breakthrough in programming came with the PC and Turbo Pascal.

Barry Garelick said...

Yes, I remember that monitor and watching my jobs bomb. There were two introductory courses to computer programming. One was relatively straightforward, but the second one assumed you had a little programming experience. By mistake I took the more advanced one. It was grueling. Assembly Language for the IBM 360.

Anonymous said...

Certainly not one of vedic math's most efficient mental math models. Some are, however, good exercises in mental math.

Anonymous said...

"the last language I learned was FORTRAN and I understand things have improved"

Whew, I should hope so. Barry you're funny.

But indeed you can't take the old-timer's AT key away.

While I do program today on the web using PERL and javascript (not OO but heck at least they're respectable in the 21st century), I STILL write DOS-like batch jobs for my laptop. They work great.

That was a true confession. Okay you can laugh now. I need laughing at.