Super interesting things about math you will definitely fall back

With the super interesting math things below, surely many of you will love this interesting subject.

What makes a great attraction of mathematics? The following will help you understand and love this subject!

1 . If you write Pi to 2 decimal places then write back, we get the word Pie, which means "circle".

2 . 111.111.111 x 111.111.111 = 12.345.678.987.654.321.

3 . The number 100 is made of the word "hundrath" meaning 120 and not 100.

4 . A Pizza with radius Z and height A will have a mass of Pi x Z x Z x A (x is a "multiplication" sign).

5 . 1089 x 9 = 9801.

6 . Students chewing gum have the ability to do math faster than those who do not chew.

7 . All roads fall to "100".

123 - 45 - 67 + 89 = 100.

123 + 4 - 5 + 67 - 89 = 100.

123 - 4 - 5 - 6 - 7 + 8 - 9 = 100.

1 + 23 - 4 + 5 + 6 + 78 - 9 = 100

8 . (6x9) + (6 + 9) = 69.

9 . According to mathematicians, there are 177,147 ways to tie a tie.

10 . When you shuffle the cards, the order of the cards can never appear in history!

11 . The most preferred number is 7.

As evidence, we have 7 deadly sins, 7 world wonders, 7 colors of the rainbow, 7 dwarfs, 7 oceans, 7 days a week .

12 . 21978 x 4 = 87912.

13 . In a room with 23 people, the probability of 2 people having the same birthday is 50%.

14. The obvious .

0.999999 . = 1

15. Kaprekar's constant

Select any 4-digit number, follow the steps below and the final result is always 6174.

6174 is called Kaprekar constant named after Indian mathematician. In order to get this constant, it must follow these steps:

Choose any 4-digit number, provided that all 4 digits do not overlap (like 1111, 2222, 3333, .). Example number 1401.

Reverse the order of the numbers so that I can choose the 2 largest and smallest numbers obtained from this overturning. In the example are two numbers 4110 and 0114.

Get the largest number minus the smallest number: 4110 - 0114 = 3996

Repeat steps 2 and 3 for the difference obtained. We have the following results:

4110 - 0114 = 3996

9963 - 3699 = 6264

6642 - 2466 = 4176

7641 - 1467 = 6174

Kaprekar's constant appears after the fourth subtraction. Starting from here if the next calculation will not get any other number than this constant.

The highest Kaprekar constant takes 7 steps (7 subtraction) to reach the final result.

Example number 9831 to 6174 after 7 subtraction:

9831 - 1389 = 8442

8442 - 2448 = 5994

9954 - 4599 = 5355

5553 - 3555 = 1998

9981 - 1899 = 8082

8820 - 0288 = 8532 (give 0 before or after for 4 numbers, not 882 - 288 = 594)

8532 - 2358 = 6174

16. Special pairs of numbers

The invention as well as the naming of numbers are followed by rules in an interesting way.

• Inviolable number : this name is given to numbers that cannot be written as the sum of all the divisors of any positive integer (regardless of that positive integer). For example, 4 is not inviolable because 4 = 3 + 1 while 3 and 1 all have an estimate of 9. But the number 5 is an inviolable number because there is only one way to write 5 = 4 + 1. If you reason that this is the sum of 4, then you are wrong because the sum of 4's estimates must be 1 + 2 = 3.
• The pair of betrothal numbers is two positive integers such that the sum of this number is one unit more than the other (not counting that number). That is (m, n) is an engaged pair of numbers if if s (m) = n + 1 and s (n) = m +1 where s (n) is the total floating part of n and a similar condition. The equivalent is σ (m) = σ (n) = m + n + 1 where σ denotes the sum function of the divisors. Therefore the first betrothal pairs were born (48,75), (140,175), (1575, 1648), (2024, 2295) .
• Rich numbers : are the numbers that the sum of the sum of that number (excluding that number) is bigger than the other. For example, the number 12 has the sum of the divisors (not including the number 12) is 1 + 2 + 3 + 4 + 6 = 16> 12. So 12 is a rich number.
• Perfect sale : is a natural number equal to the sum of all or some of its divisors, so the perfect set of numbers is larger than the perfect set of numbers. Examples are 6, 12, 18, 20, 24, 28, 30, .
• Odd numbers: some are considered odd numbers when it is a rich number but not a perfect number. In other words, the sum of its divisors is greater than that but the sum of some or all of the divisors will never be equal to that number. For example, 70, 836, 4030, 5830, . are odd numbers.

17. The meaning of numbers

For Asians numbers from 1 to 9 speak a distinct meaning that forms the idea of ​​feng shui. Specifically:

• Number 1 : is the number of gods understood as the son of heaven. Number one is a symbol of the reward, unique peaks no one else. If people cannot hold this position for a long time, it will be alone and only god can hold this position.
• Number 2 : a symbol for a couple, a couple and a happy number, running smoothly for summer events, weddings . Number 2 represents the balance of yin and yang, so red sentences Luckily, it is often posted at the gate of the gate at the beginning of the year.
• Number 3 : considered a solid number like three-legged hips and Hong Kong people whose verses three and three are forever (endless), it is also a symbol of longevity.
• Number 4 : is the formation of two pairs, but in the pronunciation of Hong Kong, it is called like a letter. So this is a bad combination.
• Number 5 : the symbol of honor, authority and power, number 5 means that the five directions are five sacred mountains. Symbolizes longevity and death.
• Number 6 : is double of numbers and so is a good omen. 3 plus 6 is 9 and create a lucky 3-digit group.
• Number 7, 8 : means 7 stars and 7-star sword used in the celebration to repel demons in the defense, some 7 or 8 decorations are given a mysterious power and a feeling inviolable.
• Number 9 : numbers of happiness, wellbeing and convenience.