## Sunday, October 11, 2015

### 10 Math/Number Facts (Vol. #3)

1. The rule of 72 : It is used as an approximation in banking and finance for the time it took an investment to double at r%. For a 10% return on investment, the approximate period would be 72/10 = 7.2 years. The rule applies to compound interest.

2. In English, the name of every odd number contains the letter E.

3. An illegal prime is a prime number that represents information whose possession or distribution is forbidden in some legal jurisdiction. One of the first illegal primes was found in 2001. When interpreted in a particular way, it describes a computer program that bypasses the digital rights management scheme used on DVDs. Distribution of such a program in the United States is illegal under the Digital Millennium Copyright Act.

4. A US company called Fractal Antenna Systems, Inc. makes antenna arrays that use fractal shapes to get superior performance characteristics, because they can be packed so close together.

This design ensures performance improvements in antennae used in wireless, microwave, RFID (Radio Frequency Identification) and telecommunications.

5. In 1796, according to an unfounded legend, the metric system was born. The Oct 10 (10/10) date seems to signify the base 10 way of using measurements. A real birth date might be 8 May 1790, when acting on a motion by a bishop, Charles Maurice de Talleyrand (1754-1838), the French National Assembly decided to create a simple, stable, decimal system of measurement units. The earliest metre unit chosen was the length of a pendulum with a half-period of a second.

6. For Pythagoras, 10 was the symbol of the universe and all human knowledge.

7. Ahmes, an Egyptian scribe, is the earliest contributor to math whose name is known. He wrote the Rhind Mathematical Papyrus, a work of Ancient Egyptian mathematics that dates to approximately 1650 BC.

8. 19 is the only prime equal to the difference of two cubed primes.
19 = 3^3 - 2^3.

9. The sum of the reciprocals of the Fibonacci numbers is: 3.3598856662431775531720113029....

10. 284 is an amicable (or friendly) number paired with 220. The divisors of 220 add up to 284 and the divisors of 284 add up to 220. Amicable numbers were known to the Pythagoreans, who credited them with many mystical properties. A general formula by which some of these numbers could be derived was invented circa 850 by Thābit ibn Qurra (826-901).

Also have a look at : Vol#2 and Vol#1

## Monday, October 5, 2015

### Look what people replied when they were asked what they use math for.

Isn't it amazing how math is being used everywhere around us.

## Friday, September 25, 2015

### Just a math nerds :)

Just a math nerds :) #mathjoke #welovemaths
Posted by We Love Maths on Thursday, September 24, 2015

## Thursday, September 24, 2015

### Tshirt for math nerds

Source : Etsy
(PS : not promoting stuff from ETSY, sharing bcoz I found it interesting)

## Friday, May 8, 2015

### This is what happens when Americans discover the Metric System

Amazon Item for Mathslovers

### Showing love via graph

Amazon Item for Mathslovers

### All these sentences are of the same length

Amazon Item for Mathslovers

## Thursday, April 30, 2015

### Square any two digits number that ends with 5 [Math Tips & Tricks]

Calculating the square of a number below 100 is extremely simple. If you want to find the square of 35 for example, you simply have to take the first digit (3), multiply it for the next higher number (4), and then add 25 to the result.

Example:

35^2 = (3x4)25 = 1225

Amazon Item for Mathslovers

### How to multiply any two digits number by 11 [Math Tips & Tricks]

For example, you want to find the product of 45 and 11. One way to find it would be to multiply 45 by 10 and then add 45 on the result. There is, however, a simple trick that’ll do the job for any two digits number. To find out the result, write the first digit followed by the addition of the first and second digit, followed by the second digit.

Example:

45 x 11 = 4(4+5)5 = 495

What happens if the sum of the two numbers is bigger than 9? In this case you add 1 to the first number, followed by the last digit of the addition of the two numbers, and then again you add the second number

57 x 11 = 5(5+7)7 = 627

Amazon Item for Mathslovers

## Wednesday, April 29, 2015

### How to propose a girl? [Pi Day ecards]

Amazon Item for Mathslovers

### Teen Sets New World Record by Solving Rubik's Cube in 5.25 Seconds

Amazon Item for Mathslovers

### How to ask for a prom Mathematically?

Amazon Item for Mathslovers

## Monday, March 16, 2015

### 10 Math/Number Facts (Vol. #2)

1. Another mnemonic for remembering the first 20 decimals of pi is

How I wish I could enumerate pi easily, since all these bullshit mnemonics prevent recalling any of pi's sequence more simply.                      (posted by abyssbrain in comment of previous post)

2. 6666 days is equal to 144 hours + 1440 hours + 14400 hours + 144000 hours.

3. One cycle of the Mayan calendar is equivalent to 5126 years. The digits 5126 begin at the 2012th decimal place of π!

4. Metric Day is celebrated each year on October 10th.

5. 68 is the smallest composite number that can be read as a prime number when it is turned upside down.

6. 71 is the largest prime p that humans will ever discover such that 2^p doesn't contain the digit 9.

7. Welsh government has declared March 14  as Pi Day Cymru as a way of honouring the Anglesey-born mathematician William Jones, who came up with the idea of pi in 1706.

8. Mats Bergsten of Sweden holds the world record for memorising pi while juggling, reciting 9,778 digits in 1hr 20min.

9. A poem written such that the length of each word is determined by the digits in pi is called a piem. A haiku written under those constraints is called a piku.

10. Among all shapes with the same perimeter, the circle has the largest area.

## Monday, March 9, 2015

### 10 Quotes on Math

1. "A mathematician is a device for turning coffee into theorems." - Alfréd Rényi

2. "Proof is the idol before whom the pure mathematician tortures himself." - Sir Arthur Eddington

3. "Mathematics is about progress and adventure and emotion" - Cédric Villani

4. "Math is not about memorizing formulas. Math is about understanding the world." - Anonymous

5. "Mathematics is capable of an artistic excellence as great as that of any music, perhaps greater." - Bertrand Russell

6. "The essence of mathematics lies precisely in its freedom." - Georg Cantor

7. "Don't just read it; fight it! Ask your own questions, look for your own examples, discover your own proofs. Is the hypothesis necessary? Is the converse true? What happens in the classical special case? What about the degenerate cases? Where does the proof use the hypothesis?" - Paul Halmos

8. "Wherever there is number, there is beauty." - Diadochus Proclus

9. "Statistics: The only science that enables different experts using the same figures to draw different conclusions." - Evan Esar

10. "But mathematics is the sister, as well as the servant, of the arts and is touched by the same madness and genius." - Marston Morse

## Saturday, March 7, 2015

### Top 10 Pi jokes for Pi day

1. What do you get when you cut a jack o’lantern by its diameter?… Pumpkin Pi!
2. What do you get when you take green cheese and divide its circumference by its diameter?… Moon Pi.
3. What do you get when you take the sun and divide its circumference by its diameter?…Pi in the sky.
4. Mathematician: “Pi r squared” Baker:” No! Pies are round, cakes are square!
5. What do we get when we take the object and order the rim by the diameter?…Pi in the sky by and by.
6. In Alaska, where it gets very cold, pi is only 3.00. As you know, everything shrinks in the cold. They call it Eskimo pi.
7. What do you get if you divide the circumference of a bowl of ice cream by its diameter?… Pi a’la mode.
8. 3.14% of Sailors are PI rates.
9. The roundest knight at King Arthur’s was Sir Cumference… He ate too much Pi!
10. What is the official animal of Pi Day?… the PI – thon!

## Wednesday, March 4, 2015

### The Relationship between a Circle and its Radius [gif]

Source : math-fail.com

### 10 Math/Number Facts

1. The word ‘hundrath’ in Old Norse, from which our ‘hundred’ derives, meant not 100 but 120.

2. 3435 - A Münchhausen Number has the property that the sum of its digits raised to themselves produces the original number. The only Münchhausen Number are 1 and 3435 (3435 = 3^3 + 4^4 + 3^3 + 5^5)

3. 2520 is the smallest number divisible by the numbers 1 through 10.

4. You can remember the value of Pi (3.1415926) by counting each word's letters in 'May I have a large container of coffee'.

5. If A=1,... Z=26, then the word PRIME is prime. (P+R+I+M+E --> 16+18+9+13+5 =61)

6. No Fibonacci number is divisible by 61.

7. 61!-60!+59!-...+1! is prime.

8. In base two number system, pi is 11.001001000011...

9. The digits 62 occur at the 61st & 62nd digits of phi, φ; AND The 61st & 62nd digits of e.

10. The 61st Fibonacci number (2,504,730,781,961) is the smallest Fibonacci number which contains all the digits from 0 to 9.

## Sunday, March 1, 2015

### Mathematical errors in motivational pic

Source : thepoke.co.uk

### Interesting factorizations| Num3ers 7928 and 7929

Recently
Benjamin Vitale posted interesting relationship between numbers 7928 and 7928 on his blog in his article article here

The two consecutive numbers can be expressed as follows

7928 = 8 * 991
7929 = 9 * 881

So, I wrote little python script to find more pairs like this and posting it as below.
And It is interesting to find that all 3-digit multipliers are ending with 1.

201 * 1 = 201 and 101 * 2 = 202
201 * 3 = 603 and 301 * 2 = 602
221 * 1 = 221 and 111 * 2 = 222
221 * 3 = 663 and 331 * 2 = 662
301 * 2 = 602 and 201 * 3 = 603
301 * 4 = 1204 and 401 * 3 = 1203
331 * 2 = 662 and 221 * 3 = 663
331 * 4 = 1324 and 441 * 3 = 1323
401 * 3 = 1203 and 301 * 4 = 1204
401 * 5 = 2005 and 501 * 4 = 2004
441 * 3 = 1323 and 331 * 4 = 1324
441 * 5 = 2205 and 551 * 4 = 2204
501 * 4 = 2004 and 401 * 5 = 2005
501 * 6 = 3006 and 601 * 5 = 3005
551 * 4 = 2204 and 441 * 5 = 2205
551 * 6 = 3306 and 661 * 5 = 3305
601 * 5 = 3005 and 501 * 6 = 3006
601 * 7 = 4207 and 701 * 6 = 4206
661 * 5 = 3305 and 551 * 6 = 3306
661 * 7 = 4627 and 771 * 6 = 4626
701 * 6 = 4206 and 601 * 7 = 4207
701 * 8 = 5608 and 801 * 7 = 5607
771 * 6 = 4626 and 661 * 7 = 4627
771 * 8 = 6168 and 881 * 7 = 6167
801 * 7 = 5607 and 701 * 8 = 5608
801 * 9 = 7209 and 901 * 8 = 7208
881 * 7 = 6167 and 771 * 8 = 6168
881 * 9 = 7929 and 991 * 8 = 7928
901 * 8 = 7208 and 801 * 9 = 7209
991 * 8 = 7928 and 881 * 9 = 7929

UPDATE

all 4-digits numbers (Those too ending with 1)

2001 * 1 = 2001 and 1001 * 2 = 2002
2001 * 3 = 6003 and 3001 * 2 = 6002
2021 * 1 = 2021 and 1011 * 2 = 2022
2021 * 3 = 6063 and 3031 * 2 = 6062
2201 * 1 = 2201 and 1101 * 2 = 2202
2201 * 3 = 6603 and 3301 * 2 = 6602
2221 * 1 = 2221 and 1111 * 2 = 2222
2221 * 3 = 6663 and 3331 * 2 = 6662
3001 * 2 = 6002 and 2001 * 3 = 6003
3001 * 4 = 12004 and 4001 * 3 = 12003
3031 * 2 = 6062 and 2021 * 3 = 6063
3031 * 4 = 12124 and 4041 * 3 = 12123
3301 * 2 = 6602 and 2201 * 3 = 6603
3301 * 4 = 13204 and 4401 * 3 = 13203
3331 * 2 = 6662 and 2221 * 3 = 6663
3331 * 4 = 13324 and 4441 * 3 = 13323
4001 * 3 = 12003 and 3001 * 4 = 12004
4001 * 5 = 20005 and 5001 * 4 = 20004
4041 * 3 = 12123 and 3031 * 4 = 12124
4041 * 5 = 20205 and 5051 * 4 = 20204
4401 * 3 = 13203 and 3301 * 4 = 13204
4401 * 5 = 22005 and 5501 * 4 = 22004
4441 * 3 = 13323 and 3331 * 4 = 13324
4441 * 5 = 22205 and 5551 * 4 = 22204
5001 * 4 = 20004 and 4001 * 5 = 20005
5001 * 6 = 30006 and 6001 * 5 = 30005
5051 * 4 = 20204 and 4041 * 5 = 20205
5051 * 6 = 30306 and 6061 * 5 = 30305
5501 * 4 = 22004 and 4401 * 5 = 22005
5501 * 6 = 33006 and 6601 * 5 = 33005
5551 * 4 = 22204 and 4441 * 5 = 22205
5551 * 6 = 33306 and 6661 * 5 = 33305
6001 * 5 = 30005 and 5001 * 6 = 30006
6001 * 7 = 42007 and 7001 * 6 = 42006
6061 * 5 = 30305 and 5051 * 6 = 30306
6061 * 7 = 42427 and 7071 * 6 = 42426
6601 * 5 = 33005 and 5501 * 6 = 33006
6601 * 7 = 46207 and 7701 * 6 = 46206
6661 * 5 = 33305 and 5551 * 6 = 33306
6661 * 7 = 46627 and 7771 * 6 = 46626
7001 * 6 = 42006 and 6001 * 7 = 42007
7001 * 8 = 56008 and 8001 * 7 = 56007
7071 * 6 = 42426 and 6061 * 7 = 42427
7071 * 8 = 56568 and 8081 * 7 = 56567
7701 * 6 = 46206 and 6601 * 7 = 46207
7701 * 8 = 61608 and 8801 * 7 = 61607
7771 * 6 = 46626 and 6661 * 7 = 46627
7771 * 8 = 62168 and 8881 * 7 = 62167
8001 * 7 = 56007 and 7001 * 8 = 56008
8001 * 9 = 72009 and 9001 * 8 = 72008
8081 * 7 = 56567 and 7071 * 8 = 56568
8081 * 9 = 72729 and 9091 * 8 = 72728
8801 * 7 = 61607 and 7701 * 8 = 61608
8801 * 9 = 79209 and 9901 * 8 = 79208
8881 * 7 = 62167 and 7771 * 8 = 62168
8881 * 9 = 79929 and 9991 * 8 = 79928
9001 * 8 = 72008 and 8001 * 9 = 72009
9091 * 8 = 72728 and 8081 * 9 = 72729
9901 * 8 = 79208 and 8801 * 9 = 79209

9991 * 8 = 79928 and 8881 * 9 = 79929

5 digits numbers (and again ending with 1)

20001 * 1 = 20001 and 10001 * 2 = 20002
20001 * 3 = 60003 and 30001 * 2 = 60002
20021 * 1 = 20021 and 10011 * 2 = 20022
20021 * 3 = 60063 and 30031 * 2 = 60062
20201 * 1 = 20201 and 10101 * 2 = 20202
20201 * 3 = 60603 and 30301 * 2 = 60602
20221 * 1 = 20221 and 10111 * 2 = 20222
20221 * 3 = 60663 and 30331 * 2 = 60662
22001 * 1 = 22001 and 11001 * 2 = 22002
22001 * 3 = 66003 and 33001 * 2 = 66002
22021 * 1 = 22021 and 11011 * 2 = 22022
22021 * 3 = 66063 and 33031 * 2 = 66062
22201 * 1 = 22201 and 11101 * 2 = 22202
22201 * 3 = 66603 and 33301 * 2 = 66602
22221 * 1 = 22221 and 11111 * 2 = 22222
22221 * 3 = 66663 and 33331 * 2 = 66662
30001 * 2 = 60002 and 20001 * 3 = 60003
30001 * 4 = 120004 and 40001 * 3 = 120003
30031 * 2 = 60062 and 20021 * 3 = 60063
30031 * 4 = 120124 and 40041 * 3 = 120123
30301 * 2 = 60602 and 20201 * 3 = 60603
30301 * 4 = 121204 and 40401 * 3 = 121203
30331 * 2 = 60662 and 20221 * 3 = 60663
30331 * 4 = 121324 and 40441 * 3 = 121323
33001 * 2 = 66002 and 22001 * 3 = 66003
33001 * 4 = 132004 and 44001 * 3 = 132003
33031 * 2 = 66062 and 22021 * 3 = 66063
33031 * 4 = 132124 and 44041 * 3 = 132123
33301 * 2 = 66602 and 22201 * 3 = 66603
33301 * 4 = 133204 and 44401 * 3 = 133203
33331 * 2 = 66662 and 22221 * 3 = 66663
33331 * 4 = 133324 and 44441 * 3 = 133323
40001 * 3 = 120003 and 30001 * 4 = 120004
40001 * 5 = 200005 and 50001 * 4 = 200004
40041 * 3 = 120123 and 30031 * 4 = 120124
40041 * 5 = 200205 and 50051 * 4 = 200204
40401 * 3 = 121203 and 30301 * 4 = 121204
40401 * 5 = 202005 and 50501 * 4 = 202004
40441 * 3 = 121323 and 30331 * 4 = 121324
40441 * 5 = 202205 and 50551 * 4 = 202204
44001 * 3 = 132003 and 33001 * 4 = 132004
44001 * 5 = 220005 and 55001 * 4 = 220004
44041 * 3 = 132123 and 33031 * 4 = 132124
44041 * 5 = 220205 and 55051 * 4 = 220204
44401 * 3 = 133203 and 33301 * 4 = 133204
44401 * 5 = 222005 and 55501 * 4 = 222004
44441 * 3 = 133323 and 33331 * 4 = 133324
44441 * 5 = 222205 and 55551 * 4 = 222204
50001 * 4 = 200004 and 40001 * 5 = 200005
50001 * 6 = 300006 and 60001 * 5 = 300005
50051 * 4 = 200204 and 40041 * 5 = 200205
50051 * 6 = 300306 and 60061 * 5 = 300305
50501 * 4 = 202004 and 40401 * 5 = 202005
50501 * 6 = 303006 and 60601 * 5 = 303005
50551 * 4 = 202204 and 40441 * 5 = 202205
50551 * 6 = 303306 and 60661 * 5 = 303305
55001 * 4 = 220004 and 44001 * 5 = 220005
55001 * 6 = 330006 and 66001 * 5 = 330005
55051 * 4 = 220204 and 44041 * 5 = 220205
55051 * 6 = 330306 and 66061 * 5 = 330305
55501 * 4 = 222004 and 44401 * 5 = 222005
55501 * 6 = 333006 and 66601 * 5 = 333005
55551 * 4 = 222204 and 44441 * 5 = 222205
55551 * 6 = 333306 and 66661 * 5 = 333305
60001 * 5 = 300005 and 50001 * 6 = 300006
60001 * 7 = 420007 and 70001 * 6 = 420006
60061 * 5 = 300305 and 50051 * 6 = 300306
60061 * 7 = 420427 and 70071 * 6 = 420426
60601 * 5 = 303005 and 50501 * 6 = 303006
60601 * 7 = 424207 and 70701 * 6 = 424206
60661 * 5 = 303305 and 50551 * 6 = 303306
60661 * 7 = 424627 and 70771 * 6 = 424626
66001 * 5 = 330005 and 55001 * 6 = 330006
66001 * 7 = 462007 and 77001 * 6 = 462006
66061 * 5 = 330305 and 55051 * 6 = 330306
66061 * 7 = 462427 and 77071 * 6 = 462426
66601 * 5 = 333005 and 55501 * 6 = 333006
66601 * 7 = 466207 and 77701 * 6 = 466206
66661 * 5 = 333305 and 55551 * 6 = 333306
66661 * 7 = 466627 and 77771 * 6 = 466626
70001 * 6 = 420006 and 60001 * 7 = 420007
70001 * 8 = 560008 and 80001 * 7 = 560007
70071 * 6 = 420426 and 60061 * 7 = 420427
70071 * 8 = 560568 and 80081 * 7 = 560567
70701 * 6 = 424206 and 60601 * 7 = 424207
70701 * 8 = 565608 and 80801 * 7 = 565607
70771 * 6 = 424626 and 60661 * 7 = 424627
70771 * 8 = 566168 and 80881 * 7 = 566167
77001 * 6 = 462006 and 66001 * 7 = 462007
77001 * 8 = 616008 and 88001 * 7 = 616007
77071 * 6 = 462426 and 66061 * 7 = 462427
77071 * 8 = 616568 and 88081 * 7 = 616567
77701 * 6 = 466206 and 66601 * 7 = 466207
77701 * 8 = 621608 and 88801 * 7 = 621607
77771 * 6 = 466626 and 66661 * 7 = 466627
77771 * 8 = 622168 and 88881 * 7 = 622167
80001 * 7 = 560007 and 70001 * 8 = 560008
80001 * 9 = 720009 and 90001 * 8 = 720008
80081 * 7 = 560567 and 70071 * 8 = 560568
80081 * 9 = 720729 and 90091 * 8 = 720728
80801 * 7 = 565607 and 70701 * 8 = 565608
80801 * 9 = 727209 and 90901 * 8 = 727208
80881 * 7 = 566167 and 70771 * 8 = 566168
80881 * 9 = 727929 and 90991 * 8 = 727928
88001 * 7 = 616007 and 77001 * 8 = 616008
88001 * 9 = 792009 and 99001 * 8 = 792008
88081 * 7 = 616567 and 77071 * 8 = 616568
88081 * 9 = 792729 and 99091 * 8 = 792728
88801 * 7 = 621607 and 77701 * 8 = 621608
88801 * 9 = 799209 and 99901 * 8 = 799208
88881 * 7 = 622167 and 77771 * 8 = 622168
88881 * 9 = 799929 and 99991 * 8 = 799928
90001 * 8 = 720008 and 80001 * 9 = 720009
90091 * 8 = 720728 and 80081 * 9 = 720729
90901 * 8 = 727208 and 80801 * 9 = 727209
90991 * 8 = 727928 and 80881 * 9 = 727929
99001 * 8 = 792008 and 88001 * 9 = 792009
99091 * 8 = 792728 and 88081 * 9 = 792729
99901 * 8 = 799208 and 88801 * 9 = 799209

99991 * 8 = 799928 and 88881 * 9 = 799929

## Friday, February 27, 2015

### Math is Everywhere - Mathematical Poster by GeoArtworks [Etsy]

Source : etsy.com

### Trick To Remember Which Sign Is Greater Than and Which Is Less Than

If you need to remember which way the greater than or less than sign should point, you can remember it this way. Think of the sign as an alligator's mouth. The alligator wants to eat the larger side. Like this:
Source : Ducksters.com

### Earth and Venus approximately trace out this pattern with 5-fold symmetry as they orbit the Sun.

Source : blog.matthen.com

### Instances when Brands had to remove advert having Negative attitude toward Math

Instance 1: When L'Oreal agreed to change 'bad at maths' boast advert. (Feb 2015)

L'Oreal Paris adverts featured British actress Dame Helen Mirren saying: "Age is just a number. And maths was never my thing."
National Numeracy tweeted its distaste that the advertising appeared to boast about poor maths skills.
L'Oreal Paris thanked the charity and pledged to change it "right away".

Instance 2 : Mattel Inc. agreed to pull talking Barbie "Math class is tough' doll (Oct 1992)

A talking Barbie doll was criticized by a national women's group for saying "math class is tough". Mattel did not order a recall but began offering a swap for anyone who bought an offending doll.
The computer chip that randomly selects four phrases for each doll picked from 269 selections, not 270.

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