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| Post Number: 1
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waltre 
FNG
Group: Members
Posts: 6
Joined: Jun. 2002
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Posted on: Jul. 01 2002,00:01 |
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Do any DetNetters know any fun mathematical methods, tricks for multiplying large numbers or interesting patterns they would like to share?
This is a very geeky pastime for some, but it is a very handy tool to be able to multiply, add, square and divide numbers in your head using easy techniques. And a lot of the time, the only thing stopping people from being good with numbers (minus a calculator), big or large, is a technique or two that they find easy to work with.
Surely someone can share their techniques, something they learned from school or a good math[s] teacher.
If anyone is interested, i have put a page up, my 'math[s] for wankers' page at fortunecity, detailing some methods of squaring two digit numbers in your head.
And I'm sure there is some clever folk out there with some neat ways to crunch numbers without so much as a pen and paper.
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Is it bad luck to take a dump on a seagull?
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| Post Number: 2
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Bob_the_Cannibal
Anonymous Coward
Group: Members
Posts: 313
Joined: Feb. 2002
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Posted on: Jul. 01 2002,00:35 |
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quick pattern of multiplication by 9.
X*9:
1| 2| 3| 4| 5| 6| 7| 8| 9|10
0| 1| 2| 3| 4| 5| 6| 7| 8| 9
9| 8| 7| 6| 5| 4| 3| 2| 1| 0
lame, yes, but it works for me.
also for factoring, if it's 2 digits, and the digits add to 9, then 9 is a factor:
54; 5+4=9, 9 and 6.
oddly, this trick helped for a problem on the ASVAB.
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| Post Number: 3
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Necromancer
Ace Rimmer
Group: Members
Posts: 419
Joined: Feb. 2002
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Posted on: Jul. 01 2002,02:25 |
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um times things by five can be made a bit easier by simply adding a 0 to the number and divding by two.
(times by ten and half)
timesing indices is easy you just add the indices together.
all the other stuff i just use a calculator cos thats the smart thing to do.
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There'll be time for explanations later... and hopefully, some sex
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| Post Number: 4
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forumwhore
Fear Me, I Am Change.
Group: Members
Posts: 3282
Joined: Dec. 2001
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Posted on: Jul. 01 2002,02:28 |
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Hot DAMN you know the plural of "index"!!!
Now if we can just educate people that
"data" is plural....
(wait, "data" *are plural? Shaddup!
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Posting from; El Pueblo de Nuestra Senora la Reina de Los Angeles de Porciuncula
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