Comments on: Fast multiplication

By: donpatma

donpatma — Sun, 28 Jun 2009 10:01:03 +0000

you are so smart
you are so smart

By: disturbedrox01

disturbedrox01 — Sun, 28 Jun 2009 10:01:03 +0000

omg!!! Thank you!
omg!!! Thank you!

By: WarFreak131

WarFreak131 — Sun, 28 Jun 2009 10:01:03 +0000

thats easy, (100(56 …
thats easy, (100(56) - 2(56))
5600 - 2*56
5600 - 112
5488

By: xxaiidaxx

xxaiidaxx — Sun, 28 Jun 2009 10:01:03 +0000

cause 98 and 56 is …
cause 98 and 56 is closer to 100.. its in the other video.. the numbers that he showed are only closer to 10..

By: lolzzzmybeotch

lolzzzmybeotch — Sun, 28 Jun 2009 10:01:03 +0000

omg ty so much for …
omg ty so much for this method genius 5/5

By: warrior004

warrior004 — Sun, 28 Jun 2009 10:01:03 +0000

yh yh…it works …
yh yh…it works whit low numbers like 13 x 13 but try do like 98 x 56 than that ign thing not work so….i say bad work !

By: HelloKittyProvider

HelloKittyProvider — Sun, 28 Jun 2009 10:01:03 +0000

I already know all …
I already know all these skills but thanks for helping us out anyway. I personally think that it’s easier when you’ve learnt all your times tables and do the calculations normally because what he did slowed down my calculation. XD lol

By: harprit1989

harprit1989 — Sun, 28 Jun 2009 10:01:03 +0000

what if it is like …
what if it is like 135×125

By: Freeze01

Freeze01 — Sun, 28 Jun 2009 10:01:03 +0000

the math behin the …
the math behin the trick:

12 can be written as 10+2, 14 as 10+4
Or more generally for any number close to 10… 10+a or 10+b

now the multiplication becomes (10+a)*(10+b)
which can be rewritten as 10(10+a+b) + a*b

So this is why it works.

By: flyingflamingwings

flyingflamingwings — Sun, 28 Jun 2009 10:01:03 +0000

Thank you for …
Thank you for posting this awesome video!!!! I can multiply Double digit numbers simply now!!!!!