Mere's Totally Random and (Mostly) Useless Maths Facts!

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Mere Intricacy

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Senior Member

11-21-2012

So for the funzies of it, and to bring a little more light-hearted-ness into OT, I have decided to, once a day, post a totally random and mostly useless math fact in this thread.

So, without further ado...

FACT #1:
Do you know how to check if a larger number is divisible by 7 with using a calculator?

One way is take the last digit in the number, double it, and minus it from the beginning numbers. If the number you're left with is divisible by 7 so was the original number.
E.g. 1855.
185 - (5 x 2)= 175.
17 - (5 x 2) = 7.
Thus 1855 is divisible by 7.

There is another test as well a tad more complicated. In this one you times each digit by a number and sum them together. Starting from the right-hand side you times each digit by 1, 3, 2, 6, 4, 5 and repeat again if there are more digits. If this sum is divisible by 7 so is the number.
E.g. 1855
(5 x 1) + (5 x 3) + (8 x 2) + (1 x 6)
= 5 + 15 + 16 + 6 = 42 which is divisible by 7.

BONUS FACT:
Did you know a square is a special type of rectangle and a circle is a special type of ellipse.

FACT #2:
Many of you may have heard of the Fibonacci Squence which is found by adding the 2 pervious numbers in the seqeunce;0, 1, 1, 2, 3, 5, 8, 13 ....

But did you know to find the nth term all you need to do is put it into his formala,without knowing the two pervious numbers...

an = (1/sqrt(5))*(((1 + sqrt(5))/2)^n + ((1 - sqrt(5)/2)^n)

Where a0 = 0 and a1 = 1.
Try it for yourself!

FACT #3:
Inequalities don't exist for complex numbers
BONUS FACT: You can't square an inequality, unless you know both sides are of the same sign.

FACT #4: Four is the only number in the English language that is spelled with the same amount of letters as it represents.
BONUS FACT: Forty is the only number that has all its letters in alphabetical order.

FACT #5: 169,518,829,100,544,000,000,000,000,000 ways to play the first ten moves in a game of chess!

FACT #6:

1 x 1 = 1
11 x 11 = 121
111 x 111 = 12321
1111 x 1111 = 1234321
11111 x 11111 = 123454321
111111 x 111111 = 12345654321
1111111 x 1111111 = 1234567654321
11111111 x 11111111 = 123456787654321
111111111 x 111111111 = 12345678987654321

BONUS FACT:

1 x 9 + 2 = 11
12 x 9 + 3 = 111
123 x 9 + 4 = 1111
1234 x 9 + 5 = 11111
12345 x 9 + 6 = 111111
123456 x 9 + 7 = 1111111
1234567 x 9 + 8 = 11111111
12345678 x 9 + 9 = 111111111
123456789 x 9 + 10 = 111111111

FACT #7
2519 Mod 2 = 1
2519 Mod 3 = 2
2519 Mod 4 = 3
2519 Mod 5 = 4
2519 Mod 6 = 5
2519 Mod 7 = 6
2519 Mod 8 = 7
2519 Mod 9 = 8
2519 Mod 10 = 9

FACT #8

Did you know 1 x 10^69 is a duovigintillion.


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the flail

Senior Member

11-21-2012

2+2=fish

=D


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Algol1

Senior Member

11-21-2012

No.


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Spanish Cobra

Member

11-21-2012

Quote:
Originally Posted by the flail View Post
2+2=fish

=D

No it's potato.


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Kohana Sushi

Senior Member

11-21-2012

Quote:
Originally Posted by Mere Intricacy View Post
BONUS FACT:[/B] Did you know a square is a special type of rectangle and a circle is a special type of ellipse.
Yes.


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Keshaldra

Senior Member

11-21-2012

To square a number that ends in "5", take the numbers before it (n), and multiply by (n+1), then slap a "25" on the end.

25 x 25

2 * 3 = 6
add a "25" on the end = 625


75 x 75
7 x 8 = 56
add a "25" on the end = 5625

105 x 105
10 x 11 = 110
add a "25" on the end = 11025


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Kohana Sushi

Senior Member

11-21-2012

Quote:
Originally Posted by Keshaldra View Post
To square a number that ends in "5", take the numbers before it (n), and multiply by (n+1), then slap a "25" on the end.

25 x 25

2 * 3 = 6
add a "25" on the end = 625


75 x 75
7 x 8 = 56
add a "25" on the end = 5625

105 x 105
10 x 11 = 110
add a "25" on the end = 11025
Stop taking attention away from Mere.


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Jesus the Friend

Member

11-21-2012

INB4 Vag squad claims Mere is attention whoring...

Oh wait, too late.

Dominick's Law #2;
As a discussion started by Mere increases in length, the probability of the vag squad or others accusing her of attention whoring approaches 1.


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OTLegend

Member

11-21-2012

Quote:
Originally Posted by Jesus the Friend View Post
INB4 Vag squad claims Mere is attention whoring...

Oh wait, too late.

Dominick's Law #2;
As a discussion started by Mere increases in length, the probability of the vag squad or others accusing her of attention whoring approaches 1.
You know how you're always whining about how women destroy men?

Do you think the damage women do to woman is more than they do to men, equal, or less?

Not exactly in the same way but the hating they do to hold eachother back.


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Jesus the Friend

Member

11-21-2012

^ Mangina in disguise.

Sure smells like a bleeding mang.


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