Pretty cool trick.

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Pretty cool trick.

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I use the box method anyway but then it takes ages to add them all up at the end.

Calculators pwn.

When my dad wakes up, I`m showing it to him. He`ll enjoy it. Silly little math freak.

Seriously. The best thing I ever did for getting good at math was lose my calculator early on in pre-calculus and not tell my parents.

And the lines would get faster in a hurry if you drew them faster. Too bad that long division is faster unless you are slow at multiplying by 7, 8, or 9, in which case you have more lines to draw.

Best part I can see about this is that it works with other base systems - suppose you want to multiply 6`b011101 by 6`b111001. Or 8`h1A by 8`h06. Could help.

Normally I just strain to figure it out until I break down and do that damned lattice method of multiplication

I imagine it has some practical application, though. Might be a fun project.

I`m not kidding.

But what if there wasa 9 hmmm?

I`d rather use a calculator

this is quite a good method if your bored and have time, its not faster but it would be fun to see what the teacher did when they saw this

these lines sure would solve that problem

/One...two...TWO boobies! Ah ah ah!!!

My year 5 teacher taught me a cool way which was in escence long division, but did in little steps and add it up all in your head. Which is why i can do 1283*134 mentally in 2 minutes when i dont have stuff to write on! lol

but it is cool in theory. i dont think i`ll ever use it tho.

WOW this is amazing.

I suppose this method would help the visual learners, but I`m a math tutor at my local college and wouldn`t recommend this trick to anyone. It`s time consuming and requires more space on the paper. Oh, and some of you may be forgetting that in lower level math classes, calculators are not permitted.

me = nerd... i know...

my brainnnnn

At the end, he carries whatever digits he needs to. It could get more complicated than he made it, with multiple carries, but that works the same as carrying in the standard way of doing these things.

This is really the same thing as doing the multiplication the regular way (except you don`t need a multiplication table), so it does work for everything, 72tour. The only thing you have to add to take care of all the cases, is that he didn`t show how to write a zero. Suppose we make zero a dotted line, and don`t count intersections with dotted lines. Then it works for everything.

The spaced out lines correspond to ones, tens, hundreds, etc., just like the numbers in the decimal system (321=3 hundreds, 2 tens, 1 one--same for the 3,2,1 lines). There are at most two sets of each type of line, one for each number. That makes it possible to do the multiplication graphically: e.g 3x2 lines will intersect each other 6 times--you can see that. Where the lines intersect it`s like multiplying one by the other: e.g., if the ten line intersects a hundred line, you`re counting thousands. So the intersection of 3 hundreds and 2 tens, or 2 hundreds and 3 tens gets you 6 thousands.

Since the lines are drawn in order, which place is which is also in order: e.g. at the bottom right, you are multiplying ones by ones, so you are counting ones. If you go one up or one to the left, you are multiplying ones by tens, so you are counting tens. Basically, every step up or to the left, moves the decimal place one to the right. That is wh

- Pretty cool trick.