Bitcoin Forum
June 19, 2024, 05:10:55 PM *
News: Voting for pizza day contest
 
   Home   Help Search Login Register More  
Pages: [1]
  Print  
Author Topic: Cool Maths Trick  (Read 838 times)
e1ghtSpace (OP)
Legendary
*
Offline Offline

Activity: 1526
Merit: 1001


Crypto since 2014


View Profile WWW
September 08, 2014, 06:16:30 AM
Last edit: September 08, 2014, 06:38:22 AM by e1ghtSpace
 #1

Here's a cool thing I found while I was bored in maths class. Here it is:
(you can change the numbers around and it still works)

2x5=10     This is what we will base our calculations off
We will also use 7 just cause.
-----------------
7x5=35
7/2=3.5

We used the 5 and the 2 and if we multiply or divide the answers by the product of the two numbers, we reach the other equation's answer.

7x5=35 / 10 = 3.5
7/2=3.5 x 10 =35

Weird, huh?

-----------------------------------------------------------------------------------------
So of you wanted to work out 13 x 25       (Because multiplying 100 is easy)
you could use this to your advantage.

25x4=100        Note: The 4 could be any number but I chose it because 4 x 25 = 100 and it's easy to multiply by 100.

13/4=3.25

3.25 x 100 = 325

So does 13 x 25 = 325?
Yes! So this thing (I don't know what to call it) works!

Comment on what you think.
Bitcoinexp
Hero Member
*****
Offline Offline

Activity: 544
Merit: 500


View Profile
September 08, 2014, 07:04:55 AM
 #2

So you mean to say that:
Since, 2 x 5 = 10
Therefore, X x 2 = X x 10/5 ? (big X is unknown, small x is multiply)
If you look carefully at the first equation, you can see the connection Tongue
I noticed it a couple of years back, when i started to learn multiplication and division Tongue
Sweet ol' times...
I didn't know what it meant back then, but now i realized that i had actually discovered something called "The fraction".
Billbags
Sr. Member
****
Offline Offline

Activity: 280
Merit: 250

Brainwashed this way


View Profile
September 08, 2014, 07:10:48 AM
Last edit: September 12, 2014, 03:14:47 PM by Billbags
 #3

                  D
60  ------------------------
       Speed x Time


We call this "60 D street" when navigating at sea.  (Distance Speed Time) we use any two we know to get the third we need.
Time is entered in minutes, speed in knots and distance in nautical miles.
The use of "60" ensures that time is calculated in minutes rather than in hours and tenths of an hour.

To find distance, if speed and time (or duration) are known:

D = (S x T) ÷ 60

To find time, if distance and speed are known:

T = (60 x D) ÷ S

To find speed, if distance and time are known:

S = (60 x D) ÷ T


Your math is very similar to this in many ways if you look closely.

Listen: meat beat manifesto ~ Edge of no control (pt.1)
Read:"He who controls the past controls the future. He who controls the present controls the past." ~ George Orwell
Think: http://unenumerated.blogspot.com/2014/12/the-dawn-of-trustworthy-computing.html
e1ghtSpace (OP)
Legendary
*
Offline Offline

Activity: 1526
Merit: 1001


Crypto since 2014


View Profile WWW
September 08, 2014, 08:43:04 AM
 #4

So you mean to say that:
Since, 2 x 5 = 10
Therefore, X x 2 = X x 10/5 ? (big X is unknown, small x is multiply)
If you look carefully at the first equation, you can see the connection Tongue
I noticed it a couple of years back, when i started to learn multiplication and division Tongue
Sweet ol' times...
I didn't know what it meant back then, but now i realized that i had actually discovered something called "The fraction".
Oh yeah. It's so simple. Didn't even notice. Thanks for pointing that out.
Ooh, you discovered this: http://en.m.wikipedia.org/wiki/Fraction_(religion) jks.
Gleb Gamow
In memoriam
VIP
Legendary
*
Offline Offline

Activity: 1428
Merit: 1145



View Profile
September 08, 2014, 08:45:14 AM
 #5

So of you wanted to work out 13 x 25       (Because multiplying 100 is easy)
you could use this to your advantage.

25x4=100        Note: The 4 could be any number but I chose it because 4 x 25 = 100 and it's easy to multiply by 100.

13/4=3.25

3.25 x 100 = 325

So does 13 x 25 = 325?



25 x 13 = X   Note: The 13 could be any number but I chose it because...

13/13 = 1

1 x X = X

So does 13 x 25 = X

Yes it does.

Q.E.D.

25 x 2 = 50   Note: The 2 could be any number but I chose it because...

13/2 = 6.50

6.50 x 50 = 325



13/x X 25x = ?

(13 X 25) X x/x = ?

(13 X 25) X 1 = ?
Pages: [1]
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!