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How to Do Cube Roots of 9 Digit Numbers in Your Head
1729.com — A method for doing cube roots of 9 digit numbers in your head. Show the world you are a mental arithmetic genius!
pdorrell- 844 diggs
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- catullus, on 10/12/2007, -0/+0what? you mean you can't already do that? psssh.
- BugMeNot2, on 10/12/2007, -0/+0Some people aren't all that good in math, y' know?
- osrevad, on 10/12/2007, -0/+0That's the whole point of this.
- masterofshadows, on 10/12/2007, -0/+0interesting read
- WeetaBiX, on 10/12/2007, -1/+0Whats a cube root?
- Less, on 10/12/2007, -0/+0yes, really rather simple. school arythmetics.
nice.
digg for you - t3hX, on 10/12/2007, -1/+0Dugg into the ground :(
- angelwspr, on 10/12/2007, -1/+0i'm a mathemagician...
- tempusrob, on 10/12/2007, -0/+0WeetaBiX: http://en.wikipedia.org/wiki/Cube_root
In short, the cube root of 8 is 2 (2*2*2 = 8). The cube root of 27 is 3 (3*3*3=27). Etc... - vinnievegas, on 10/12/2007, -0/+0Could someone please explain the formula to get the mod 10 numbers? He doesnt explain that. He just says it is add, subtrac, and multiply. Could someone please explain?
- matx, on 10/12/2007, -0/+01 + 1 = 3
- amihaic, on 10/12/2007, -0/+0this is absolutely rivetizzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
- vinnievegas, on 10/12/2007, -0/+0[quote]1 + 1 = 3[/quote]
that isnt the formula... please someone explain! - jonohull, on 10/12/2007, -0/+1For the mod 10 numbers, you just do the operation (+,-,* whatever), and take the last number. 3^3 mod 10 would be 7 because 2(7).
- catullus, on 10/12/2007, -0/+0haha @bugmenot2: it was a joke.
- cappslite, on 10/12/2007, -0/+0So.. what's a mod?
- ZeroLogic, on 10/12/2007, -0/+0What is Mod (modulo)??
http://en.wikipedia.org/wiki/Modulo - ZeroLogic, on 10/12/2007, -0/+0Not that any of the information in that wiki or the linked related info explained it to me.
- burke, on 10/12/2007, -0/+0For modulo 10 (as in the article)
21358097 --> 7
12 --> 2
123 --> 3
1 --> 1
See the pattern? Its just the last digit. - burke, on 10/12/2007, -0/+0oh. except then you look at that table and see what the numbers are *really* supposed to be... Just read it again, you'll get it.
- rifter, on 10/12/2007, -0/+0This article is so trivial its worthless. Its basically a "magic" trick with math. He goes to say you can't do it for *every* number, you can only do it to a certain amount.
"Don't ask them to supply a random 9 digit number, because a random 9 digit number probably won't be a cube of a whole number, and you will be in trouble, and the following strategies won't work." - bill.clark, on 10/12/2007, -0/+0Come on... we're already seen as geeks for knowing how to turn a computer on without throwing it out the window in frustration. Do we really need to push the envelope with silly ass parlor tricks? Who's going to give me a ride to Math Club? :P
- techmonk, on 10/12/2007, -0/+0yeah... nice ...but utterly useless. I once learned all the tricks to multiply upto 5 digit numbers in a snap. did i ever used it with my TI in hand? no. Do I remember it, now that I've lost practice? No. Will I use its logic ever to write a program? Absurd.
- capajc, on 10/12/2007, -0/+0Ha, I just won $5 with this. Dugg.
It's true: math tricks will not get you hot chicks. But neither will eschewing math tricks for image's sake. So why not learn? Might get you $5 every now and then.
"Hey baby, I don't know any math tricks. Wanna hook up?" Good luck. - omnithrope, on 10/12/2007, -0/+0Is there any practical use?
- arkan, on 10/12/2007, -0/+1I learned how to do this when I was in 8th grade, more then 15 years ago. In 10th grade and true geek fashion, I got a first date with a girl by betting her I could do it, a second date by teaching her how I did it. Four years after that we were married, and somehow, we're still married.
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