Human Calculator

I'm having a problem with 86x31...the calculator says it's 2666 but when i use you way it gives me 1766...what am i doing wrong...please reply at andrei21us@yahoo.com plz it's urgent

LOL

Thats a nice ... um ... trick ... still looks that a calculator comes in handy here...but nice vid anyway!

Very easy to use, maybe one thing though, there seems to be many different tricks for numbers close to ten, numbers close to 100 etc...
What about the numbers not close to 10 or 100 etc...?
What if one remembers the wrong trick while mentally calculating?

Just a thought, keep the tricks coming, they're great!

hey dude I think that you are a math teacher or if you are not then you got it from a math teacher but whatever that is so nice from you to share it with us,,,othersdont do!!!

quality stuff!!! keep it up

What is 92*94 by your method it is 9008 but the answer is 8348

what if one or both factors are not close to 100? how is it?? for example...85x94=?

tahnks

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how do u do this with smaaller numbers such as 23x10...?

I teach cable theory for a major cable provider and will use this in my class as a class opener. I just cannot figure out why someone would post a negative comment on such a good video? Good stuff here, and don't let the negative comments get you down. Keep it going!

All I have to say thanks...and keep it up..totally awesome videos..

Congrats, you just managed to piss me off with the 'cross your heart' #$@#% what da @#$#....where's my shotgun when I need it...you'r only alive cause it's illegal to shoot you....

Cool... I like it... Now i can calculate soooo fast... :):) Thanks for the trick... :):) Keep it up...

a x b (where a, b < 100)
= (100 - i) x (100 - j) (where 100 - i = a, 100 - j = b)
= 100x100 - 100i - 100j + i*j
= (100 - i - j)*100 + i * j
= (a - j)*100 + i*j or (b - i) * 100 + i*j
(where i = 100 -a, j = 100 -b)

5*****

great teacher ! all give him 5 stars for this great find :)

Thanks for sharing. I stuggled through calculas 1, that's as far as I got.

Female models sexy pictures at: just kidding, why can't metacafe do more about these spammers that are infecting the threads.

This is so cool. Im in college for computer science and we have a lot of math so any trick that helps me is appreciated.

holy crap, this is amazing!

it works so well and so quickly, only problem is i cant subtract
if i had a good trick for subtracting numbers from 100 faster then it would be incredible

i could calculate that in 4 seconds with a calculator without thinking and i bet you could figure out 58X32 in 5 seconds well guess what a calculator can. crap video.